Added the transaction management.

src/accounting/__init__.py

@@ -73,6 +73,9 @@ def init_app(app: Flask, user_utils: AbstractUserUtils,
     from . import currency
     currency.init_app(app, bp)
 
+    from . import transaction
+    transaction.init_app(app, bp)
+
     from .utils import next_uri
     next_uri.init_app(bp)
 

src/accounting/models.py

@@ -17,8 +17,11 @@
 """The data models.
 
 """
+from __future__ import annotations
+
 import re
 import typing as t
+from decimal import Decimal
 
 import sqlalchemy as sa
 from flask import current_app
@@ -26,6 +29,7 @@ from flask_babel import get_locale
 from sqlalchemy import text
 
 from accounting import db
+from accounting.locale import gettext
 from accounting.utils.user import user_cls, user_pk_column
 
 
@@ -134,6 +138,8 @@ class Account(db.Model):
     l10n = db.relationship("AccountL10n", back_populates="account",
                            lazy=False)
     """The localized titles."""
+    entries = db.relationship("JournalEntry", back_populates="account")
+    """The journal entries."""
 
     __CASH = "1111-001"
     """The code of the cash account,"""
@@ -197,6 +203,25 @@ class Account(db.Model):
                 return
         self.l10n.append(AccountL10n(locale=current_locale, title=value))
 
+    @property
+    def is_in_use(self) -> bool:
+        """Returns whether the account is in use.
+
+        :return: True if the account is in use, or False otherwise.
+        """
+        if not hasattr(self, "__is_in_use"):
+            setattr(self, "__is_in_use", len(self.entries) > 0)
+        return getattr(self, "__is_in_use")
+
+    @is_in_use.setter
+    def is_in_use(self, is_in_use: bool) -> None:
+        """Sets whether the account is in use.
+
+        :param is_in_use: True if the account is in use, or False otherwise.
+        :return: None.
+        """
+        setattr(self, "__is_in_use", is_in_use)
+
     @classmethod
     def find_by_code(cls, code: str) -> t.Self | None:
         """Finds an account by its code.
@@ -251,6 +276,14 @@ class Account(db.Model):
                                 cls.base_code != "3353")\
             .order_by(cls.base_code, cls.no).all()
 
+    @property
+    def query_values(self) -> list[str]:
+        """Returns the values to be queried.
+
+        :return: The values to be queried.
+        """
+        return [self.code, self.title_l10n] + [x.title for x in self.l10n]
+
     @classmethod
     def cash(cls) -> t.Self:
         """Returns the cash account.
@@ -370,6 +403,8 @@ class Currency(db.Model):
     l10n = db.relationship("CurrencyL10n", back_populates="currency",
                            lazy=False)
     """The localized names."""
+    entries = db.relationship("JournalEntry", back_populates="currency")
+    """The journal entries."""
 
     def __str__(self) -> str:
         """Returns the string representation of the currency.
@@ -450,3 +485,215 @@ class CurrencyL10n(db.Model):
     """The locale."""
     name = db.Column(db.String, nullable=False)
     """The localized name."""
+
+
+class TransactionCurrency:
+    """A currency in a transaction."""
+
+    def __init__(self, code: str, debit: list[JournalEntry],
+                 credit: list[JournalEntry]):
+        """Constructs the currency in the transaction.
+
+        :param code: The currency code.
+        :param debit: The debit entries.
+        :param credit: The credit entries.
+        """
+        self.code: str = code
+        """The currency code."""
+        self.debit: list[JournalEntry] = debit
+        """The debit entries."""
+        self.credit: list[JournalEntry] = credit
+        """The credit entries."""
+
+    @property
+    def name(self) -> str:
+        """Returns the currency name.
+
+        :return: The currency name.
+        """
+        return db.session.get(Currency, self.code).name
+
+    @property
+    def debit_total(self) -> Decimal:
+        """Returns the total amount of the debit journal entries.
+
+        :return: The total amount of the debit journal entries.
+        """
+        return sum([x.amount for x in self.debit])
+
+    @property
+    def credit_total(self) -> str:
+        """Returns the total amount of the credit journal entries.
+
+        :return: The total amount of the credit journal entries.
+        """
+        return sum([x.amount for x in self.credit])
+
+
+class Transaction(db.Model):
+    """A transaction."""
+    __tablename__ = "accounting_transactions"
+    """The table name."""
+    id = db.Column(db.Integer, nullable=False, primary_key=True,
+                   autoincrement=False)
+    """The transaction ID."""
+    date = db.Column(db.Date, nullable=False)
+    """The date."""
+    no = db.Column(db.Integer, nullable=False, default=text("1"))
+    """The account number under the date."""
+    note = db.Column(db.String)
+    """The note."""
+    created_at = db.Column(db.DateTime(timezone=True), nullable=False,
+                           server_default=db.func.now())
+    """The time of creation."""
+    created_by_id = db.Column(db.Integer,
+                              db.ForeignKey(user_pk_column,
+                                            onupdate="CASCADE"),
+                              nullable=False)
+    """The ID of the creator."""
+    created_by = db.relationship(user_cls, foreign_keys=created_by_id)
+    """The creator."""
+    updated_at = db.Column(db.DateTime(timezone=True), nullable=False,
+                           server_default=db.func.now())
+    """The time of last update."""
+    updated_by_id = db.Column(db.Integer,
+                              db.ForeignKey(user_pk_column,
+                                            onupdate="CASCADE"),
+                              nullable=False)
+    """The ID of the updator."""
+    updated_by = db.relationship(user_cls, foreign_keys=updated_by_id)
+    """The updator."""
+    entries = db.relationship("JournalEntry", back_populates="transaction")
+    """The journal entries."""
+
+    def __str__(self) -> str:
+        """Returns the string representation of this transaction.
+
+        :return: The string representation of this transaction.
+        """
+        if self.is_cash_expense:
+            return gettext("Cash Expense Transaction#%(id)s", id=self.id)
+        if self.is_cash_income:
+            return gettext("Cash Income Transaction#%(id)s", id=self.id)
+        return gettext("Transfer Transaction#%(id)s", id=self.id)
+
+    @property
+    def currencies(self) -> list[TransactionCurrency]:
+        """Returns the journal entries categorized by their currencies.
+
+        :return: The currency categories.
+        """
+        entries: list[JournalEntry] = sorted(self.entries, key=lambda x: x.no)
+        codes: list[str] = []
+        by_currency: dict[str, list[JournalEntry]] = {}
+        for entry in entries:
+            if entry.currency_code not in by_currency:
+                codes.append(entry.currency_code)
+                by_currency[entry.currency_code] = []
+            by_currency[entry.currency_code].append(entry)
+        return [TransactionCurrency(code=x,
+                                    debit=[y for y in by_currency[x]
+                                           if y.is_debit],
+                                    credit=[y for y in by_currency[x]
+                                            if not y.is_debit])
+                for x in codes]
+
+    @property
+    def is_cash_income(self) -> bool:
+        """Returns whether this is a cash income transaction.
+
+        :return: True if this is a cash income transaction, or False otherwise.
+        """
+        for currency in self.currencies:
+            if len(currency.debit) > 1:
+                return False
+            if currency.debit[0].account.code != "1111-001":
+                return False
+        return True
+
+    @property
+    def is_cash_expense(self) -> bool:
+        """Returns whether this is a cash expense transaction.
+
+        :return: True if this is a cash expense transaction, or False
+            otherwise.
+        """
+        for currency in self.currencies:
+            if len(currency.credit) > 1:
+                return False
+            if currency.credit[0].account.code != "1111-001":
+                return False
+        return True
+
+    def delete(self) -> None:
+        """Deletes the transaction.
+
+        :return: None.
+        """
+        JournalEntry.query\
+            .filter(JournalEntry.transaction_id == self.id).delete()
+        db.session.delete(self)
+
+
+class JournalEntry(db.Model):
+    """An accounting journal entry."""
+    __tablename__ = "accounting_journal_entries"
+    """The table name."""
+    id = db.Column(db.Integer, nullable=False, primary_key=True,
+                   autoincrement=False)
+    """The entry ID."""
+    transaction_id = db.Column(db.Integer,
+                               db.ForeignKey(Transaction.id,
+                                             onupdate="CASCADE",
+                                             ondelete="CASCADE"),
+                               nullable=False)
+    """The transaction ID."""
+    transaction = db.relationship(Transaction, back_populates="entries")
+    """The transaction."""
+    is_debit = db.Column(db.Boolean, nullable=False)
+    """True for a debit entry, or False for a credit entry."""
+    no = db.Column(db.Integer, nullable=False)
+    """The entry number under the transaction and debit or credit."""
+    pay_off_target_id = db.Column(db.Integer,
+                                  db.ForeignKey(id, onupdate="CASCADE"),
+                                  nullable=True)
+    """The ID of the pay-off target entry."""
+    pay_off_target = db.relationship("JournalEntry", back_populates="pay_off",
+                                     remote_side=id, passive_deletes=True)
+    """The pay-off target entry."""
+    pay_off = db.relationship("JournalEntry", back_populates="pay_off_target")
+    """The pay-off entries."""
+    currency_code = db.Column(db.String,
+                              db.ForeignKey(Currency.code, onupdate="CASCADE"),
+                              nullable=False)
+    """The currency code."""
+    currency = db.relationship(Currency, back_populates="entries")
+    """The currency."""
+    account_id = db.Column(db.Integer,
+                           db.ForeignKey(Account.id,
+                                         onupdate="CASCADE"),
+                           nullable=False)
+    """The account ID."""
+    account = db.relationship(Account, back_populates="entries", lazy=False)
+    """The account."""
+    summary = db.Column(db.String, nullable=True)
+    """The summary."""
+    amount = db.Column(db.Numeric(14, 2), nullable=False)
+    """The amount."""
+
+    @property
+    def eid(self) -> int | None:
+        """Returns the journal entry ID.  This is the alternative name of the
+        ID field, to work with WTForms.
+
+        :return: The journal entry ID.
+        """
+        return self.id
+
+    @property
+    def account_code(self) -> str:
+        """Returns the account code.
+
+        :return: The account code.
+        """
+        return self.account.code

src/accounting/static/css/style.css

@@ -65,6 +65,50 @@
     overflow-y: scroll;
 }
 
+/** The transaction management */
+.accounting-currency-control {
+    background-color: transparent;
+}
+.accounting-currency-content {
+    width: calc(100% - 3rem);
+}
+.accounting-entry-content {
+    width: calc(100% - 3rem);
+    background-color: transparent;
+}
+.accounting-entry-control {
+    border-color: transparent;
+}
+.accounting-transaction-card {
+    padding: 2em 1.5em;
+    margin: 1em;
+    background-color: #F8F9FA;
+    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
+}
+.accounting-transaction-card h2 {
+    border-bottom: thick double slategray;
+}
+.accounting-list-group-stripped .list-group-item:nth-child(2n+1) {
+    background-color: #f2f2f2;
+}
+.accounting-list-group-stripped .list-group-item-success:nth-child(2n+1) {
+    background-color: #c7dbd2;
+}
+.accounting-list-group-hover .list-group-item:hover {
+    background-color: #ececec;
+}
+.accounting-transaction-entry {
+    border: none;
+}
+.accounting-transaction-entry-header {
+    font-weight: bolder;
+    border-bottom: thick double slategray;
+}
+.list-group-item.accounting-transaction-entry-total {
+    font-weight: bolder;
+    border-top: thick double slategray;
+}
+
 /* The Material Design text field (floating form control in Bootstrap) */
 .accounting-material-text-field {
     position: relative;
@@ -103,6 +147,36 @@
 .accounting-material-fab .btn:hover, .accounting-material-fab .btn:focus {
     box-shadow: 0 5px 5px -3px rgba(0, 0, 0, 0.2), 0 8px 10px 1px rgba(0, 0, 0, 0.14), 0 3px 14px 2px rgba(0,0,0,.12);
 }
+.accounting-btn-material-fab {
+    transition: transform .1s ease-in-out, right .1s ease-in-out, bottom .1s ease-in-out;
+}
+.show .accounting-btn-material-fab {
+    transform: scale(1.5) rotate(-45deg);
+}
+.accounting-material-fab-speed-dial-group {
+    position: absolute;
+    right: -2rem;
+    bottom: -7rem;
+    text-align: right;
+    opacity: 0;
+    transform: scale(0.1);
+    line-height: 5.5rem;
+    transition: opacity .1s ease-in-out, transform .1s ease-in-out, right .1s ease-in-out, bottom .1s ease-in-out;
+}
+.show .accounting-material-fab-speed-dial-group {
+    opacity: 1;
+    transform: scale(0.6);
+    right: -0.5rem;
+    bottom: 0.7rem;
+}
+.accounting-material-fab-speed-dial-group .btn {
+    background-color: white;
+    white-space: nowrap;
+    box-shadow: 0 3px 5px -1px rgba(0, 0, 0, 0.2), 0 6px 10px 0 rgba(0, 0, 0, 0.14), 0 1px 18px 0 rgba(0,0,0,.12);
+}
+.accounting-material-fab-speed-dial-group .btn:hover, .accounting-material-fab-speed-dial-group .btn:focus {
+    box-shadow: 0 5px 5px -3px rgba(0, 0, 0, 0.2), 0 8px 10px 1px rgba(0, 0, 0, 0.14), 0 3px 14px 2px rgba(0,0,0,.12);
+}
 
 /* The Material Design form switch */
 @media(max-width:767px) {

src/accounting/static/js/material-fab-speed-dial.js

@@ -0,0 +1,44 @@
+/* The Mia! Accounting Flask Project
+ * material-fab-speed-dial.js: The JavaScript for the speed dial for the material floating buttons
+ */
+
+/*  Copyright (c) 2023 imacat.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/* Author: imacat@mail.imacat.idv.tw (imacat)
+ * First written: 2023/2/25
+ */
+
+// Initializes the page JavaScript.
+document.addEventListener("DOMContentLoaded", function () {
+    initializeMaterialFabSpeedDial();
+});
+
+/**
+ * Initializes the speed dial of the material floating buttons.
+ *
+ * @private
+ */
+function initializeMaterialFabSpeedDial() {
+    const btnFab = document.getElementById("accounting-btn-material-fab-speed-dial");
+    const fab = document.getElementById(btnFab.dataset.target);
+    btnFab.onclick = function () {
+        if (fab.classList.contains("show")) {
+            fab.classList.remove("show");
+        } else {
+            fab.classList.add("show");
+        }
+    }
+}

src/accounting/static/js/transaction-form.js

@@ -0,0 +1,832 @@
+/* The Mia! Accounting Flask Project
+ * transaction-transfer-form.js: The JavaScript for the transfer transaction form
+ */
+
+/*  Copyright (c) 2023 imacat.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/* Author: imacat@mail.imacat.idv.tw (imacat)
+ * First written: 2023/2/25
+ */
+
+// Initializes the page JavaScript.
+document.addEventListener("DOMContentLoaded", function () {
+    initializeCurrencyForms();
+    initializeJournalEntries();
+    initializeAccountSelectors();
+    initializeFormValidation();
+});
+
+/**
+ * Escapes the HTML special characters and returns.
+ *
+ * @param s {string} the original string
+ * @returns {string} the string with HTML special character escaped
+ * @private
+ */
+function escapeHtml(s) {
+    return String(s)
+         .replaceAll("&", "&")
+         .replaceAll("<", "&lt;")
+         .replaceAll(">", "&gt;")
+         .replaceAll("\"", "&quot;");
+}
+
+/**
+ * Formats a Decimal number.
+ *
+ * @param number {Decimal} the Decimal number
+ * @returns {string} the formatted Decimal number
+ */
+function formatDecimal(number) {
+    if (number.equals(new Decimal("0"))) {
+        return "-";
+    }
+    const frac = number.modulo(1);
+    const whole = Number(number.minus(frac)).toLocaleString();
+    return whole + String(frac).substring(1);
+}
+
+/**
+ * Initializes the currency forms.
+ *
+ * @private
+ */
+function initializeCurrencyForms() {
+    const form = document.getElementById("accounting-form");
+    const btnNew = document.getElementById("accounting-btn-new-currency");
+    const currencyList = document.getElementById("accounting-currency-list");
+    const deleteButtons = Array.from(document.getElementsByClassName("accounting-btn-delete-currency"));
+    const onReorder = function () {
+        const currencies = Array.from(currencyList.children);
+        for (let i = 0; i < currencies.length; i++) {
+            const no = document.getElementById(currencies[i].dataset.prefix + "-no");
+            no.value = String(i + 1);
+        }
+    };
+    btnNew.onclick = function () {
+        const currencies = Array.from(document.getElementsByClassName("accounting-currency"));
+        let maxIndex = 0;
+        currencies.forEach(function (currency) {
+            const index = parseInt(currency.dataset.index);
+            if (maxIndex < index) {
+                maxIndex = index;
+            }
+        });
+        const newIndex = String(maxIndex + 1);
+        const html = form.dataset.currencyTemplate
+            .replaceAll("CURRENCY_INDEX", escapeHtml(newIndex));
+        currencyList.insertAdjacentHTML("beforeend", html);
+        const newEntryButtons = Array.from(document.getElementsByClassName("accounting-currency-" + newIndex + "-btn-new-entry"));
+        const btnDelete = document.getElementById("accounting-btn-delete-currency-" + newIndex);
+        newEntryButtons.forEach(initializeNewEntryButton);
+        initializeBtnDeleteCurrency(btnDelete);
+        resetDeleteCurrencyButtons();
+        initializeDragAndDropReordering(currencyList, onReorder);
+    };
+    deleteButtons.forEach(initializeBtnDeleteCurrency);
+    initializeDragAndDropReordering(currencyList, onReorder);
+}
+
+/**
+ * Initializes the button to delete a currency.
+ *
+ * @param button {HTMLButtonElement} the button to delete a currency.
+ * @private
+ */
+function initializeBtnDeleteCurrency(button) {
+    const target = document.getElementById(button.dataset.target);
+    button.onclick = function () {
+        target.parentElement.removeChild(target);
+        resetDeleteCurrencyButtons();
+    };
+}
+
+/**
+ * Resets the status of the delete currency buttons.
+ *
+ * @private
+ */
+function resetDeleteCurrencyButtons() {
+    const buttons = Array.from(document.getElementsByClassName("accounting-btn-delete-currency"));
+    if (buttons.length > 1) {
+        buttons.forEach(function (button) {
+            button.classList.remove("d-none");
+        });
+    } else {
+        buttons[0].classList.add("d-none");
+    }
+}
+
+/**
+ * Initializes the journal entry forms.
+ *
+ * @private
+ */
+function initializeJournalEntries() {
+    const newButtons = Array.from(document.getElementsByClassName("accounting-btn-new-entry"));
+    const entryLists = Array.from(document.getElementsByClassName("accounting-entry-list"));
+    const entries = Array.from(document.getElementsByClassName("accounting-entry"))
+    const deleteButtons = Array.from(document.getElementsByClassName("accounting-btn-delete-entry"));
+    newButtons.forEach(initializeNewEntryButton);
+    entryLists.forEach(initializeJournalEntryListReorder);
+    entries.forEach(initializeJournalEntry);
+    deleteButtons.forEach(initializeDeleteJournalEntryButton);
+    initializeJournalEntryFormModal();
+}
+
+/**
+ * Initializes the button to add a new journal entry.
+ *
+ * @param button {HTMLButtonElement} the button to add a new journal entry
+ */
+function initializeNewEntryButton(button) {
+    const entryForm = document.getElementById("accounting-entry-form");
+    const formAccountControl = document.getElementById("accounting-entry-form-account-control");
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    const formAccountError = document.getElementById("accounting-entry-form-account-error")
+    const formSummary = document.getElementById("accounting-entry-form-summary");
+    const formSummaryError = document.getElementById("accounting-entry-form-summary-error");
+    const formAmount = document.getElementById("accounting-entry-form-amount");
+    const formAmountError = document.getElementById("accounting-entry-form-amount-error");
+    button.onclick = function () {
+        entryForm.dataset.currencyIndex = button.dataset.currencyIndex;
+        entryForm.dataset.entryType = button.dataset.entryType;
+        entryForm.dataset.entryIndex = button.dataset.entryIndex;
+        formAccountControl.classList.remove("accounting-not-empty")
+        formAccountControl.classList.remove("is-invalid");
+        formAccountControl.dataset.bsTarget = button.dataset.accountModal;
+        formAccount.innerText = "";
+        formAccount.dataset.code = "";
+        formAccount.dataset.text = "";
+        formAccountError.innerText = "";
+        formSummary.value = "";
+        formSummary.classList.remove("is-invalid");
+        formSummaryError.innerText = ""
+        formAmount.value = "";
+        formAmount.classList.remove("is-invalid");
+        formAmountError.innerText = "";
+    };
+}
+
+/**
+ * Initializes the reordering of a journal entry list.
+ *
+ * @param entryList {HTMLUListElement} the journal entry list.
+ */
+function initializeJournalEntryListReorder(entryList) {
+    initializeDragAndDropReordering(entryList, function () {
+        const entries = Array.from(entryList.children);
+        for (let i = 0; i < entries.length; i++) {
+            const no = document.getElementById(entries[i].dataset.prefix + "-no");
+            no.value = String(i + 1);
+        }
+    });
+}
+
+/**
+ * Initializes the journal entry.
+ *
+ * @param entry {HTMLLIElement} the journal entry.
+ */
+function initializeJournalEntry(entry) {
+    const entryForm = document.getElementById("accounting-entry-form");
+    const accountCode = document.getElementById(entry.dataset.prefix + "-account-code");
+    const summary = document.getElementById(entry.dataset.prefix + "-summary");
+    const amount = document.getElementById(entry.dataset.prefix + "-amount");
+    const control = document.getElementById(entry.dataset.prefix + "-control");
+    const formAccountControl = document.getElementById("accounting-entry-form-account-control");
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    const formSummary = document.getElementById("accounting-entry-form-summary");
+    const formAmount = document.getElementById("accounting-entry-form-amount");
+    control.onclick = function () {
+        entryForm.dataset.currencyIndex = entry.dataset.currencyIndex;
+        entryForm.dataset.entryType = entry.dataset.entryType;
+        entryForm.dataset.entryIndex = entry.dataset.entryIndex;
+        if (accountCode.value === "") {
+            formAccountControl.classList.remove("accounting-not-empty");
+        } else {
+            formAccountControl.classList.add("accounting-not-empty");
+        }
+        formAccountControl.dataset.bsTarget = entry.dataset.accountModal;
+        formAccount.innerText = accountCode.dataset.text;
+        formAccount.dataset.code = accountCode.value;
+        formAccount.dataset.text = accountCode.dataset.text;
+        formSummary.value = summary.value;
+        formAmount.value = amount.value;
+        validateJournalEntryForm();
+    };
+}
+
+/**
+ * Initializes the journal entry form modal.
+ *
+ * @private
+ */
+function initializeJournalEntryFormModal() {
+    const entryForm = document.getElementById("accounting-entry-form");
+    const formAccountControl = document.getElementById("accounting-entry-form-account-control");
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    const formSummary = document.getElementById("accounting-entry-form-summary");
+    const formAmount = document.getElementById("accounting-entry-form-amount");
+    const modal = document.getElementById("accounting-entry-form-modal");
+    formAccountControl.onclick = function () {
+        const prefix = "accounting-" + entryForm.dataset.entryType + "-account";
+        const query = document.getElementById(prefix + "-selector-query")
+        const more = document.getElementById(prefix + "-more");
+        const options = Array.from(document.getElementsByClassName(prefix + "-option"));
+        const btnClear = document.getElementById(prefix + "-btn-clear");
+        query.value = "";
+        more.classList.remove("d-none");
+        filterAccountOptions(prefix);
+        options.forEach(function (option) {
+            if (option.dataset.code === formAccount.dataset.code) {
+                option.classList.add("active");
+            } else {
+                option.classList.remove("active");
+            }
+        });
+        if (formAccount.dataset.code === "") {
+            btnClear.classList.add("btn-secondary");
+            btnClear.classList.remove("btn-danger");
+            btnClear.disabled = true;
+        } else {
+            btnClear.classList.add("btn-danger");
+            btnClear.classList.remove("btn-secondary");
+            btnClear.disabled = false;
+        }
+    };
+    formSummary.onchange = validateJournalEntrySummary;
+    formAmount.onchange = validateJournalEntryAmount;
+    entryForm.onsubmit = function () {
+        if (validateJournalEntryForm()) {
+            saveJournalEntryForm();
+            bootstrap.Modal.getInstance(modal).hide();
+        }
+        return false;
+    }
+}
+
+/**
+ * Validates the journal entry form modal.
+ *
+ * @return {boolean} true if the form is valid, or false otherwise.
+ * @private
+ */
+function validateJournalEntryForm() {
+    let isValid = true;
+    isValid = validateJournalEntryAccount() && isValid;
+    isValid = validateJournalEntrySummary() && isValid;
+    isValid = validateJournalEntryAmount() && isValid
+    return isValid;
+}
+
+/**
+ * Validates the account in the journal entry form modal.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntryAccount() {
+    const field = document.getElementById("accounting-entry-form-account");
+    const error = document.getElementById("accounting-entry-form-account-error");
+    const control = document.getElementById("accounting-entry-form-account-control");
+    if (field.dataset.code === "") {
+        control.classList.add("is-invalid");
+        error.innerText = A_("Please select the account.");
+        return false;
+    }
+    control.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates the summary in the journal entry form modal.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntrySummary() {
+    const field = document.getElementById("accounting-entry-form-summary");
+    const error = document.getElementById("accounting-entry-form-summary-error");
+    field.value = field.value.trim();
+    field.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates the amount in the journal entry form modal.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntryAmount() {
+    const field = document.getElementById("accounting-entry-form-amount");
+    const error = document.getElementById("accounting-entry-form-amount-error");
+    field.value = field.value.trim();
+    field.classList.remove("is-invalid");
+    if (field.value === "") {
+        field.classList.add("is-invalid");
+        error.innerText = A_("Please fill in the amount.");
+        return false;
+    }
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Saves the journal entry form modal to the form.
+ *
+ * @private
+ */
+function saveJournalEntryForm() {
+    const form = document.getElementById("accounting-form");
+    const entryForm = document.getElementById("accounting-entry-form");
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    const formSummary = document.getElementById("accounting-entry-form-summary");
+    const formAmount = document.getElementById("accounting-entry-form-amount");
+    const currencyIndex = entryForm.dataset.currencyIndex;
+    const entryType = entryForm.dataset.entryType;
+    let entryIndex;
+    if (entryForm.dataset.entryIndex === "new") {
+        const entries = Array.from(document.getElementsByClassName("accounting-currency-" + currencyIndex + "-" + entryType));
+        const entryList = document.getElementById("accounting-currency-" + currencyIndex + "-" + entryType + "-list")
+        let maxIndex = 0;
+        entries.forEach(function (entry) {
+            const index = parseInt(entry.dataset.entryIndex);
+            if (maxIndex < index) {
+                maxIndex = index;
+            }
+        });
+        entryIndex = String(maxIndex + 1);
+        const html = form.dataset.entryTemplate
+            .replaceAll("CURRENCY_INDEX", escapeHtml(currencyIndex))
+            .replaceAll("ENTRY_TYPE", escapeHtml(entryType))
+            .replaceAll("ENTRY_INDEX", escapeHtml(entryIndex));
+        entryList.insertAdjacentHTML("beforeend", html);
+        initializeJournalEntryListReorder(entryList);
+    } else {
+        entryIndex = entryForm.dataset.entryIndex;
+    }
+    const currency = document.getElementById("accounting-currency-" + currencyIndex);
+    const entry = document.getElementById("accounting-currency-" + currencyIndex + "-" + entryType + "-" + entryIndex);
+    const accountCode = document.getElementById(entry.dataset.prefix + "-account-code");
+    const accountText = document.getElementById(entry.dataset.prefix + "-account-text");
+    const summary = document.getElementById(entry.dataset.prefix + "-summary");
+    const summaryText = document.getElementById(entry.dataset.prefix + "-summary-text");
+    const amount = document.getElementById(entry.dataset.prefix + "-amount");
+    const amountText = document.getElementById(entry.dataset.prefix + "-amount-text");
+    accountCode.value = formAccount.dataset.code;
+    accountCode.dataset.text = formAccount.dataset.text;
+    accountText.innerText = formAccount.dataset.text;
+    summary.value = formSummary.value;
+    summaryText.innerText = formSummary.value;
+    amount.value = formAmount.value;
+    amountText.innerText = formatDecimal(new Decimal(formAmount.value));
+    if (entryForm.dataset.entryIndex === "new") {
+        const btnDelete = document.getElementById(entry.dataset.prefix + "-btn-delete");
+        initializeJournalEntry(entry);
+        initializeDeleteJournalEntryButton(btnDelete);
+        resetDeleteJournalEntryButtons(btnDelete.dataset.sameClass);
+    }
+    updateBalance(currencyIndex, entryType);
+    validateJournalEntriesReal(currencyIndex, entryType);
+    validateBalance(currency);
+}
+
+/**
+ * Initializes the button to delete a journal entry.
+ *
+ * @param button {HTMLButtonElement} the button to delete a journal entry
+ */
+function initializeDeleteJournalEntryButton(button) {
+    const target = document.getElementById(button.dataset.target);
+    const currencyIndex = target.dataset.currencyIndex;
+    const entryType = target.dataset.entryType;
+    const currency = document.getElementById("accounting-currency-" + currencyIndex);
+    button.onclick = function () {
+        target.parentElement.removeChild(target);
+        resetDeleteJournalEntryButtons(button.dataset.sameClass);
+        updateBalance(currencyIndex, entryType);
+        validateJournalEntriesReal(currencyIndex, entryType);
+        validateBalance(currency);
+    };
+}
+
+/**
+ * Resets the status of the delete journal entry buttons.
+ *
+ * @param sameClass {string} the class of the buttons
+ * @private
+ */
+function resetDeleteJournalEntryButtons(sameClass) {
+    const buttons = Array.from(document.getElementsByClassName(sameClass));
+    if (buttons.length > 1) {
+        buttons.forEach(function (button) {
+            button.classList.remove("d-none");
+        });
+    } else {
+        buttons[0].classList.add("d-none");
+    }
+}
+
+/**
+ * Updates the balance.
+ *
+ * @param currencyIndex {string} the currency index.
+ * @param entryType {string} the journal entry type, either "debit" or "credit"
+ * @private
+ */
+function updateBalance(currencyIndex, entryType) {
+    const prefix = "accounting-currency-" + currencyIndex + "-" + entryType;
+    const amounts = Array.from(document.getElementsByClassName(prefix + "-amount"));
+    const totalText = document.getElementById(prefix + "-total");
+    let total = new Decimal("0");
+    amounts.forEach(function (amount) {
+        if (amount.value !== "") {
+            total = total.plus(new Decimal(amount.value));
+        }
+    });
+    totalText.innerText = formatDecimal(total);
+}
+
+/**
+ * Initializes the account selectors.
+ *
+ * @private
+ */
+function initializeAccountSelectors() {
+    const selectors = Array.from(document.getElementsByClassName("accounting-selector-modal"));
+    const formAccountControl = document.getElementById("accounting-entry-form-account-control");
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    selectors.forEach(function (selector) {
+        const more = document.getElementById(selector.dataset.prefix + "-more");
+        const btnClear = document.getElementById(selector.dataset.prefix + "-btn-clear");
+        const options = Array.from(document.getElementsByClassName(selector.dataset.prefix + "-option"));
+        more.onclick = function () {
+            more.classList.add("d-none");
+            filterAccountOptions(selector.dataset.prefix);
+        };
+        initializeAccountQuery(selector);
+        btnClear.onclick = function () {
+            formAccountControl.classList.remove("accounting-not-empty");
+            formAccount.innerText = "";
+            formAccount.dataset.code = "";
+            formAccount.dataset.text = "";
+            validateJournalEntryAccount();
+        };
+        options.forEach(function (option) {
+            option.onclick = function () {
+                formAccountControl.classList.add("accounting-not-empty");
+                formAccount.innerText = option.dataset.content;
+                formAccount.dataset.code = option.dataset.code;
+                formAccount.dataset.text = option.dataset.content;
+                validateJournalEntryAccount();
+            };
+        });
+    });
+}
+
+/**
+ * Initializes the query on the account options.
+ *
+ * @param selector {HTMLDivElement} the selector modal
+ * @private
+ */
+function initializeAccountQuery(selector) {
+    const query = document.getElementById(selector.dataset.prefix + "-selector-query");
+    query.addEventListener("input", function () {
+        filterAccountOptions(selector.dataset.prefix);
+    });
+}
+
+/**
+ * Filters the account options.
+ *
+ * @param prefix {string} the HTML ID and class prefix
+ * @private
+ */
+function filterAccountOptions(prefix) {
+    const query = document.getElementById(prefix + "-selector-query");
+    const optionList = document.getElementById(prefix + "-option-list");
+    if (optionList === null) {
+        console.log(prefix + "-option-list");
+    }
+    const options = Array.from(document.getElementsByClassName(prefix + "-option"));
+    const more = document.getElementById(prefix + "-more");
+    const queryNoResult = document.getElementById(prefix + "-option-no-result");
+    const codesInUse = getAccountCodeUsedInForm();
+    let hasAnyMatched = false;
+    options.forEach(function (option) {
+        const isMatched = shouldAccountOptionShow(option, more, codesInUse, query);
+        if (isMatched) {
+            option.classList.remove("d-none");
+            hasAnyMatched = true;
+        } else {
+            option.classList.add("d-none");
+        }
+    });
+    if (!hasAnyMatched) {
+        optionList.classList.add("d-none");
+        queryNoResult.classList.remove("d-none");
+    } else {
+        optionList.classList.remove("d-none");
+        queryNoResult.classList.add("d-none");
+    }
+}
+
+/**
+ * Returns whether an account option should show.
+ *
+ * @param option {HTMLLIElement} the account option
+ * @param more {HTMLLIElement} the more account element
+ * @param inUse {string[]} the account codes that are used in the form
+ * @param query {HTMLInputElement} the query element, if any
+ * @return {boolean} true if the account option should show, or false otherwise
+ * @private
+ */
+function shouldAccountOptionShow(option, more, inUse, query) {
+    const isQueryMatched = function () {
+        if (query.value === "") {
+            return true;
+        }
+        const queryValues = JSON.parse(option.dataset.queryValues);
+        for (const queryValue of queryValues) {
+            if (queryValue.includes(query.value)) {
+                return true;
+            }
+        }
+        return false;
+    };
+    const isMoreMatched = function () {
+        if (more.classList.contains("d-none")) {
+            return true;
+        }
+        return option.classList.contains("accounting-account-in-use") || inUse.includes(option.dataset.code);
+    };
+    return isMoreMatched() && isQueryMatched();
+}
+
+/**
+ * Returns the account codes that are used in the form.
+ *
+ * @return {string[]} the account codes that are used in the form
+ * @private
+ */
+function getAccountCodeUsedInForm() {
+    const accountCodes = Array.from(document.getElementsByClassName("accounting-account-code"));
+    const formAccount = document.getElementById("accounting-entry-form-account");
+    const inUse = [formAccount.dataset.code];
+    accountCodes.forEach(function (accountCode) {
+        inUse.push(accountCode.value);
+    });
+    return inUse
+}
+
+/**
+ * Initializes the form validation.
+ *
+ * @private
+ */
+function initializeFormValidation() {
+    const date = document.getElementById("accounting-date");
+    const note = document.getElementById("accounting-note");
+    const form = document.getElementById("accounting-form");
+    date.onchange = validateDate;
+    note.onchange = validateNote;
+    form.onsubmit = validateForm;
+}
+
+/**
+ * Validates the form.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateForm() {
+    let isValid = true;
+    isValid = validateDate() && isValid;
+    isValid = validateCurrencies() && isValid;
+    isValid = validateNote() && isValid;
+    return isValid;
+}
+
+/**
+ * Validates the date.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateDate() {
+    const field = document.getElementById("accounting-date");
+    const error = document.getElementById("accounting-date-error");
+    field.value = field.value.trim();
+    field.classList.remove("is-invalid");
+    if (field.value === "") {
+        field.classList.add("is-invalid");
+        error.innerText = A_("Please fill in the date.");
+        return false;
+    }
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates the currency sub-forms.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateCurrencies() {
+    const currencies = Array.from(document.getElementsByClassName("accounting-currency"));
+    let isValid = true;
+    isValid = validateCurrenciesReal() && isValid;
+    currencies.forEach(function (currency) {
+        isValid = validateCurrency(currency) && isValid;
+    });
+    return isValid;
+}
+
+/**
+ * Validates the currency sub-forms, the validator itself.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateCurrenciesReal() {
+    const field = document.getElementById("accounting-currencies");
+    const error = document.getElementById("accounting-currencies-error");
+    const currencies = Array.from(document.getElementsByClassName("accounting-currency"));
+    if (currencies.length === 0) {
+        field.classList.add("is-invalid");
+        error.innerText = A_("Please add some currencies.");
+        return false;
+    }
+    field.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates a currency sub-form.
+ *
+ * @param currency {HTMLDivElement} the currency sub-form
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateCurrency(currency) {
+    const prefix = "accounting-currency-" + currency.dataset.index;
+    const debit = document.getElementById(prefix + "-debit");
+    const credit = document.getElementById(prefix + "-credit");
+    let isValid = true;
+    if (debit !== null) {
+        isValid = validateJournalEntries(currency, "debit") && isValid;
+    }
+    if (credit !== null) {
+        isValid = validateJournalEntries(currency, "credit") && isValid;
+    }
+    if (debit !== null && credit !== null) {
+        isValid = validateBalance(currency) && isValid;
+    }
+    return isValid;
+}
+
+/**
+ * Validates the journal entries in a currency sub-form.
+ *
+ * @param currency {HTMLDivElement} the currency
+ * @param entryType {string} the journal entry type, either "debit" or "credit"
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntries(currency, entryType) {
+    const currencyIndex = currency.dataset.index;
+    const entries = Array.from(document.getElementsByClassName("accounting-currency-" + currencyIndex + "-" + entryType));
+    let isValid = true;
+    isValid = validateJournalEntriesReal(currencyIndex, entryType) && isValid;
+    entries.forEach(function (entry) {
+        isValid = validateJournalEntry(entry) && isValid;
+    })
+    return isValid;
+}
+
+/**
+ * Validates the journal entries, the validator itself.
+ *
+ * @param currencyIndex {string} the currency index
+ * @param entryType {string} the journal entry type, either "debit" or "credit"
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntriesReal(currencyIndex, entryType) {
+    const prefix = "accounting-currency-" + currencyIndex + "-" + entryType;
+    const field = document.getElementById(prefix);
+    const error = document.getElementById(prefix + "-error");
+    const entries = Array.from(document.getElementsByClassName(prefix));
+    if (entries.length === 0) {
+        field.classList.add("is-invalid");
+        error.innerText = A_("Please add some journal entries.");
+        return false;
+    }
+    field.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates a journal entry sub-form in a currency sub-form.
+ *
+ * @param entry {HTMLLIElement} the journal entry
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateJournalEntry(entry) {
+    const control = document.getElementById(entry.dataset.prefix + "-control");
+    const error = document.getElementById(entry.dataset.prefix + "-error");
+    const accountCode = document.getElementById(entry.dataset.prefix + "-account-code");
+    const amount = document.getElementById(entry.dataset.prefix + "-amount");
+    if (accountCode.value === "") {
+        control.classList.add("is-invalid");
+        error.innerText = A_("Please select the account.");
+        return false;
+    }
+    if (amount.value === "") {
+        control.classList.add("is-invalid");
+        error.innerText = A_("Please fill in the amount.");
+        return false;
+    }
+    control.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+/**
+ * Validates the balance of a currency sub-form.
+ *
+ * @param currency {HTMLDivElement} the currency sub-form
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateBalance(currency) {
+    const prefix = "accounting-currency-" + currency.dataset.index;
+    const control = document.getElementById(prefix + "-control");
+    const error = document.getElementById(prefix + "-error");
+    const debit = document.getElementById(prefix + "-debit");
+    const debitAmounts = Array.from(document.getElementsByClassName(prefix + "-debit-amount"));
+    const credit = document.getElementById(prefix + "-credit");
+    const creditAmounts = Array.from(document.getElementsByClassName(prefix + "-credit-amount"));
+    if (debit !== null && credit !== null) {
+        let debitTotal = new Decimal("0");
+        debitAmounts.forEach(function (amount) {
+            if (amount.value !== "") {
+                debitTotal = debitTotal.plus(new Decimal(amount.value));
+            }
+        });
+        let creditTotal = new Decimal("0");
+        creditAmounts.forEach(function (amount) {
+            if (amount.value !== "") {
+                creditTotal = creditTotal.plus(new Decimal(amount.value));
+            }
+        });
+        if (!debitTotal.equals(creditTotal)) {
+            control.classList.add("is-invalid");
+            error.innerText = A_("The totals of the debit and credit amounts do not match.");
+            return false;
+        }
+    }
+    control.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}
+
+
+/**
+ * Validates the note.
+ *
+ * @return {boolean} true if valid, or false otherwise
+ * @private
+ */
+function validateNote() {
+    const field = document.getElementById("accounting-note");
+    const error = document.getElementById("accounting-note-error");
+    field.value = field.value
+         .replace(/^\s*\n/, "")
+         .replace(/\s+$/, "");
+    field.classList.remove("is-invalid");
+    error.innerText = "";
+    return true;
+}

src/accounting/static/js/transaction-order.js

@@ -0,0 +1,37 @@
+/* The Mia! Accounting Flask Project
+ * transaction-order.js: The JavaScript for the transaction order
+ */
+
+/*  Copyright (c) 2023 imacat.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/* Author: imacat@mail.imacat.idv.tw (imacat)
+ * First written: 2023/2/26
+ */
+
+// Initializes the page JavaScript.
+document.addEventListener("DOMContentLoaded", function () {
+    const list = document.getElementById("accounting-order-list");
+    if (list !== null) {
+        const onReorder = function () {
+            const accounts = Array.from(list.children);
+            for (let i = 0; i < accounts.length; i++) {
+                const no = document.getElementById("accounting-order-" + accounts[i].dataset.id + "-no");
+                no.value = String(i + 1);
+            }
+        };
+        initializeDragAndDropReordering(list, onReorder);
+    }
+});

src/accounting/templates/accounting/include/nav.html

@@ -26,6 +26,12 @@ First written: 2023/1/26
       {{ A_("Accounting") }}
     </span>
     <ul class="dropdown-menu">
+      <li>
+        <a class="dropdown-item {% if request.endpoint.startswith("accounting.transaction.") %} active {% endif %}" href="{{ url_for("accounting.transaction.list") }}">
+          <i class="fa-solid fa-receipt"></i>
+          {{ A_("Transactions") }}
+        </a>
+      </li>
       <li>
         <a class="dropdown-item {% if request.endpoint.startswith("accounting.account.") %} active {% endif %}" href="{{ url_for("accounting.account.list") }}">
           <i class="fa-solid fa-list"></i>

src/accounting/templates/accounting/transaction/expense/create.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+create.html: The cash expense transaction creation form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/expense/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Add a New Cash Expense Transaction") }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ request.args.get("next") or url_for("accounting.transaction.list") }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.store", txn_type=txn_type) }}{% endblock %}

src/accounting/templates/accounting/transaction/expense/detail.html

@@ -0,0 +1,53 @@
+{#
+The Mia! Accounting Flask Project
+detail.html: The account detail
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/transaction/include/detail.html" %}
+
+{% block transaction_currencies %}
+  {% for currency in obj.currencies %}
+    <div class="mb-3">
+      <div class="mb-2 fw-bolder">{{ currency.name }}</div>
+
+      <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
+        <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Content") }}</li>
+        {% for entry in currency.debit %}
+          <li class="list-group-item accounting-transaction-entry">
+            <div class="d-flex justify-content-between">
+              <div>
+                <div class="small">{{ entry.account }}</div>
+                {% if entry.summary is not none %}
+                  <div>{{ entry.summary }}</div>
+                {% endif %}
+              </div>
+              <div>{{ entry.amount|accounting_txn_format_amount }}</div>
+            </div>
+          </li>
+        {% endfor %}
+        <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
+          <div class="d-flex justify-content-between">
+            <div>{{ _("Total") }}</div>
+            <div>{{ currency.debit_total|accounting_txn_format_amount }}</div>
+          </div>
+        </li>
+      </ul>
+    </div>
+  {% endfor %}
+{% endblock %}

src/accounting/templates/accounting/transaction/expense/edit.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+edit.html: The cash expense transaction edit form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/expense/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Editing %(txn)s", txn=txn) }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ url_for("accounting.transaction.detail", txn=txn)|accounting_inherit_next }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.update", txn=txn)|accounting_txn_with_type }}{% endblock %}

src/accounting/templates/accounting/transaction/expense/include/form-currency-item.html

@@ -0,0 +1,83 @@
+{#
+The Mia! Accounting Flask Project
+currency-sub-form.html: The currency sub-form in the cash expense transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
+    <div class="d-flex justify-content-between mt-2 mb-3">
+      <div class="form-floating accounting-currency-content">
+        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+          {% for currency in accounting_txn_currency_options() %}
+            <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
+          {% endfor %}
+        </select>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
+      </div>
+
+      <div>
+        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+          <i class="fas fa-minus"></i>
+        </button>
+      </div>
+    </div>
+
+    <div class="mb-3">
+      <div id="accounting-currency-{{ currency_index }}-debit" class="form-control accounting-material-text-field accounting-not-empty {% if debit_errors %} is-invalid {% endif %}">
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-debit">{{ A_("Content") }}</label>
+        <ul id="accounting-currency-{{ currency_index }}-debit-list" class="list-group accounting-entry-list">
+          {% for entry_form in debit_forms %}
+            {% with currency_index = currency_index,
+                    entry_type = "debit",
+                    entry_index = loop.index,
+                    entry_id = entry_form.eid.data,
+                    only_one_entry_form = debit_forms|length == 1,
+                    account_code_data = "" if entry_form.account_code.data is none else entry_form.account_code.data,
+                    account_code_error = entry_form.account_code.errors,
+                    account_text = entry_form.account_text,
+                    summary_data = "" if entry_form.summary.data is none else entry_form.summary.data,
+                    summary_errors = entry_form.summary.errors,
+                    amount_data = "" if entry_form.amount.data is none else entry_form.amount.data,
+                    amount_errors = entry_form.amount.errors,
+                    amount_text = entry_form.amount.data|accounting_txn_format_amount,
+                    entry_errors = entry_form.all_errors %}
+              {% include "accounting/transaction/include/form-entry-item.html" %}
+            {% endwith %}
+          {% endfor %}
+        </ul>
+
+        <div class="d-flex justify-content-between mb-2">
+          <div>{{ A_("Total") }}</div>
+          <div><span id="accounting-currency-{{ currency_index }}-debit-total" class="badge rounded-pill bg-primary">{{ debit_total }}</span></div>
+        </div>
+
+        <div>
+          <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-entry-index="new" data-account-modal="#accounting-debit-account-selector-modal" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            <i class="fas fa-plus"></i>
+            {{ A_("New") }}
+          </button>
+        </div>
+      </div>
+      <div id="accounting-currency-{{ currency_index }}-debit-error" class="invalid-feedback">{% if debit_errors %}{{ debit_errors[0] }}{% endif %}</div>
+    </div>
+  </div>
+  <div id="accounting-currency-{{ currency_index }}-error" class="invalid-feedback">{% if currency_errors %}{{ currency_errors[0] }}{% endif %}</div>
+</div>

src/accounting/templates/accounting/transaction/expense/include/form.html

@@ -0,0 +1,50 @@
+{#
+The Mia! Accounting Flask Project
+form.html: The cash expense transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/include/form.html" %}
+
+{% block currency_sub_forms %}
+  {% if form.currencies %}
+    {% for currency_form in form.currencies %}
+      {% with currency_index = loop.index,
+              only_one_currency_form = form.currencies|length == 1,
+              currency_errors = currency_form.whole_form.errors,
+              currency_code_data = currency_form.code.data,
+              currency_code_errors = currency_form.code.errors,
+              debit_forms = currency_form.debit,
+              debit_errors = currency_form.debit_errors,
+              debit_total = currency_form.form.debit_total|accounting_txn_format_amount %}
+        {% include "accounting/transaction/expense/include/form-currency-item.html" %}
+      {% endwith %}
+    {% endfor %}
+  {% else %}
+    {% with currency_index = 1,
+            only_one_currency_form = True,
+            currency_code_data = accounting_txn_default_currency_code(),
+            debit_total = "-" %}
+      {% include "accounting/transaction/expense/include/form-currency-item.html" %}
+    {% endwith %}
+  {% endif %}
+{% endblock %}
+
+{% block account_selector_modals %}
+  {% include "accounting/transaction/include/debit-account-modal.html" %}
+{% endblock %}

src/accounting/templates/accounting/transaction/include/add-new-material-fab.html

@@ -0,0 +1,39 @@
+{#
+The Mia! Accounting Flask Project
+add-new-material-fab.html: The material floating action buttons to add a new transaction
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% if accounting_can_edit() %}
+  <div id="accounting-material-fab-speed-dial" class="d-md-none accounting-material-fab">
+    <div id="accounting-material-fab-speed-dial-actions" class="d-md-none accounting-material-fab-speed-dial-group">
+      <a class="btn rounded-pill" href="{{ url_for("accounting.transaction.create", txn_type=types.expense)|accounting_append_next }}">
+        {{ A_("Cash expense") }}
+      </a>
+      <a class="btn rounded-pill" href="{{ url_for("accounting.transaction.create", txn_type=types.income)|accounting_append_next }}">
+        {{ A_("Cash income") }}
+      </a>
+      <a class="btn rounded-pill" href="{{ url_for("accounting.transaction.create", txn_type=types.transfer)|accounting_append_next }}">
+        {{ A_("Transfer") }}
+      </a>
+    </div>
+    <button id="accounting-btn-material-fab-speed-dial" class="btn btn-primary rounded-circle accounting-btn-material-fab" type="button" data-target="accounting-material-fab-speed-dial">
+      <i class="fas fa-plus"></i>
+    </button>
+  </div>
+{% endif %}

src/accounting/templates/accounting/transaction/include/credit-account-modal.html

@@ -0,0 +1,54 @@
+{#
+The Mia! Accounting Flask Project
+credit-modals.html: The modals for the credit journal entry sub-form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-credit-account-selector-modal" class="modal fade accounting-selector-modal" data-prefix="accounting-credit-account" tabindex="-1" aria-labelledby="accounting-credit-account-selector-modal-label" aria-hidden="true">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h1 class="modal-title fs-5" id="accounting-credit-account-selector-modal-label">{{ A_("Select Credit Account") }}</h1>
+        <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal" aria-label="{{ A_("Close") }}"></button>
+      </div>
+      <div class="modal-body">
+        <div class="input-group mb-2">
+          <input id="accounting-credit-account-selector-query" class="form-control form-control-sm" type="search" placeholder=" " required="required">
+          <label class="input-group-text" for="accounting-credit-account-selector-query">
+            <i class="fa-solid fa-magnifying-glass"></i>
+            {{ A_("Search") }}
+          </label>
+        </div>
+
+        <ul id="accounting-credit-account-option-list" class="list-group accounting-selector-list">
+          {% for account in form.credit_account_options %}
+          <li id="accounting-credit-account-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-credit-account-option {% if account.is_in_use %} accounting-account-in-use {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            {{ account }}
+          </li>
+          {% endfor %}
+          <li id="accounting-credit-account-more" class="list-group-item accounting-clickable">{{ A_("More…") }}</li>
+        </ul>
+        <p id="accounting-credit-account-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Cancel") }}</button>
+        <button id="accounting-credit-account-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Clear") }}</button>
+      </div>
+    </div>
+  </div>
+</div>

src/accounting/templates/accounting/transaction/include/debit-account-modal.html

@@ -0,0 +1,54 @@
+{#
+The Mia! Accounting Flask Project
+credit-modals.html: The modals for the debit journal entry sub-form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-debit-account-selector-modal" class="modal fade accounting-selector-modal" data-prefix="accounting-debit-account" tabindex="-1" aria-labelledby="accounting-debit-account-selector-modal-label" aria-hidden="true">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h1 class="modal-title fs-5" id="accounting-debit-account-selector-modal-label">{{ A_("Select Debit Account") }}</h1>
+        <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal" aria-label="{{ A_("Close") }}"></button>
+      </div>
+      <div class="modal-body">
+        <div class="input-group mb-2">
+          <input id="accounting-debit-account-selector-query" class="form-control form-control-sm" type="search" placeholder=" " required="required">
+          <label class="input-group-text" for="accounting-debit-account-selector-query">
+            <i class="fa-solid fa-magnifying-glass"></i>
+            {{ A_("Search") }}
+          </label>
+        </div>
+
+        <ul id="accounting-debit-account-option-list" class="list-group accounting-selector-list">
+          {% for account in form.debit_account_options %}
+          <li id="accounting-debit-account-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-debit-account-option {% if account.is_in_use %} accounting-account-in-use {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            {{ account }}
+          </li>
+          {% endfor %}
+          <li id="accounting-debit-account-more" class="list-group-item accounting-clickable">{{ A_("More…") }}</li>
+        </ul>
+        <p id="accounting-debit-account-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Cancel") }}</button>
+        <button id="accounting-debit-account-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Clear") }}</button>
+      </div>
+    </div>
+  </div>
+</div>

src/accounting/templates/accounting/transaction/include/detail.html

@@ -0,0 +1,111 @@
+{#
+The Mia! Accounting Flask Project
+detail.html: The account detail
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/base.html" %}
+
+{% block header %}{% block title %}{{ obj }}{% endblock %}{% endblock %}
+
+{% block content %}
+
+<div class="btn-group mb-3">
+  <a class="btn btn-primary" href="{{ url_for("accounting.transaction.list")|accounting_or_next }}">
+    <i class="fa-solid fa-circle-chevron-left"></i>
+    {{ A_("Back") }}
+  </a>
+  {% if accounting_can_edit() %}
+    <a class="btn btn-primary d-none d-md-inline" href="{{ url_for("accounting.transaction.edit", txn=obj)|accounting_inherit_next }}">
+      <i class="fa-solid fa-gear"></i>
+      {{ A_("Settings") }}
+    </a>
+  {% endif %}
+  <a class="btn btn-primary" href="{{ url_for("accounting.transaction.order", txn_date=obj.date)|accounting_append_next }}">
+    <i class="fa-solid fa-bars-staggered"></i>
+    {{ A_("Order") }}
+  </a>
+  {% if accounting_can_edit() %}
+    <button class="btn btn-danger" type="button" data-bs-toggle="modal" data-bs-target="#accounting-delete-modal">
+      <i class="fa-solid fa-trash"></i>
+      {{ A_("Delete") }}
+    </button>
+  {% endif %}
+</div>
+
+{% if accounting_can_edit() %}
+  <div class="d-md-none accounting-material-fab">
+    <a class="btn btn-primary" href="{{ url_for("accounting.transaction.edit", txn=obj)|accounting_inherit_next }}">
+      <i class="fa-solid fa-pen-to-square"></i>
+    </a>
+  </div>
+{% endif %}
+
+{% if accounting_can_edit() %}
+  <form action="{{ url_for("accounting.transaction.delete", txn=obj) }}" method="post">
+    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+    {% if "next" in request.args %}
+      <input type="hidden" name="next" value="{{ request.args["next"] }}">
+    {% endif %}
+    <div class="modal fade" id="accounting-delete-modal" tabindex="-1" aria-labelledby="accounting-delete-modal-label" aria-hidden="true">
+      <div class="modal-dialog">
+        <div class="modal-content">
+          <div class="modal-header">
+            <h1 class="modal-title fs-5" id="accounting-delete-modal-label">{{ A_("Delete Transaction Confirmation") }}</h1>
+            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="{{ A_("Close") }}"></button>
+          </div>
+          <div class="modal-body">
+            {{ A_("Do you really want to delete this transaction?") }}
+          </div>
+          <div class="modal-footer">
+            <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ A_("Cancel") }}</button>
+            <button type="submit" class="btn btn-danger">{{ A_("Confirm") }}</button>
+          </div>
+        </div>
+      </div>
+    </div>
+  </form>
+{% endif %}
+
+<div class="accounting-transaction-card">
+  <div class="d-none d-sm-flex justify-content-center mb-3">
+    <h2 class="text-center">{{ obj }}</h2>
+  </div>
+
+  <div class="mb-3">
+    {{ obj.date|accounting_txn_format_date }}
+  </div>
+
+  {% block transaction_currencies %}{% endblock %}
+
+  {% if obj.note %}
+    <div class="card mb-3">
+      <div class="card-body">
+        <i class="far fa-comment-dots"></i>
+        {{ obj.note|accounting_txn_text2html|safe }}
+      </div>
+    </div>
+  {% endif %}
+
+  <div class="small text-secondary fst-italic">
+    <div>{{ A_("Created") }} {{ obj.created_at }} {{ obj.created_by }}</div>
+    <div>{{ A_("Updated") }} {{ obj.updated_at }} {{ obj.updated_by }}</div>
+  </div>
+</div>
+
+{% endblock %}

src/accounting/templates/accounting/transaction/include/entry-form-modal.html

@@ -0,0 +1,58 @@
+{#
+The Mia! Accounting Flask Project
+entry-form-modal.html: The modal of the journal entry sub-form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<form id="accounting-entry-form" data-currency-index="" data-entry-type="" data-entry-index="">
+  <div id="accounting-entry-form-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-entry-form-modal-label" aria-hidden="true">
+    <div class="modal-dialog">
+      <div class="modal-content">
+        <div class="modal-header">
+          <h1 class="modal-title fs-5" id="accounting-entry-form-modal-label">{{ A_("Journal Entry Content") }}</h1>
+          <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="{{ A_("Close") }}"></button>
+        </div>
+        <div class="modal-body">
+          <div class="mb-3">
+            <div id="accounting-entry-form-account-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="">
+              <label class="form-label" for="accounting-entry-form-account">{{ A_("Account") }}</label>
+              <div id="accounting-entry-form-account" data-code="" data-text=""></div>
+            </div>
+            <div id="accounting-entry-form-account-error" class="invalid-feedback"></div>
+          </div>
+
+          <div class="form-floating mb-3">
+            <input id="accounting-entry-form-summary" class="form-control" type="text" value="" placeholder=" ">
+            <label for="accounting-entry-form-summary">{{ A_("Summary") }}</label>
+            <div id="accounting-entry-form-summary-error" class="invalid-feedback"></div>
+          </div>
+
+          <div class="form-floating mb-3">
+            <input id="accounting-entry-form-amount" class="form-control" type="number" value="" min="0.01" max="" step="0.01" placeholder=" " required="required">
+            <label for="accounting-entry-form-amount">{{ A_("Amount") }}</label>
+            <div id="accounting-entry-form-amount-error" class="invalid-feedback"></div>
+          </div>
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ A_("Cancel") }}</button>
+          <button id="accounting-entry-form-btn-save" type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
+        </div>
+      </div>
+    </div>
+  </div>
+</form>

src/accounting/templates/accounting/transaction/include/form-entry-item.html

@@ -0,0 +1,46 @@
+{#
+The Mia! Accounting Flask Project
+entry-sub-form.html: The journal entry sub-form in the transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<li id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}" class="list-group-item list-group-item-action d-flex justify-content-between accounting-entry accounting-currency-{{ currency_index }}-{{ entry_type }}" data-currency-index="{{ currency_index }}" data-entry-type="{{ entry_type }}" data-entry-index="{{ entry_index }}" data-account-modal="#accounting-{{ entry_type }}-account-selector-modal" data-prefix="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}">
+  {% if entry_id %}
+    <input type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-eid" value="{{ entry_id }}">
+  {% endif %}
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-no" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-no" value="{{ entry_index }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account-code" class="accounting-account-code" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account_code" value="{{ account_code_data }}" data-text="{{ account_text }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary" value="{{ summary_data }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" class="accounting-currency-{{ currency_index }}-{{ entry_type }}-amount" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" value="{{ amount_data }}">
+  <div class="accounting-entry-content">
+    <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-control" class="form-control clickable d-flex justify-content-between accounting-entry-control {% if entry_errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+      <div>
+        <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account-text" class="small">{{ account_text }}</div>
+        <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary-text">{{ "" if summary_data is none else summary_data }}</div>
+      </div>
+      <div><span id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount-text" class="badge rounded-pill bg-primary">{{ amount_data }}</span></div>
+    </div>
+    <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-error" class="invalid-feedback">{% if entry_errors %}{{ entry_errors[0] }}{% endif %}</div>
+  </div>
+
+  <div>
+    <button id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-btn-delete" class="btn btn-danger rounded-circle accounting-btn-delete-entry accounting-currency-{{ currency_index }}-{{ entry_type }}-btn-delete-entry {% if only_one_entry_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}" data-same-class="accounting-currency-{{ currency_index }}-{{ entry_type }}-btn-delete-entry">
+      <i class="fas fa-minus"></i>
+    </button>
+  </div>
+</li>

src/accounting/templates/accounting/transaction/include/form.html

@@ -0,0 +1,90 @@
+{#
+The Mia! Accounting Flask Project
+form.html: The transfer transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/base.html" %}
+
+{% block accounting_scripts %}
+  <script src="{{ url_for("accounting.static", filename="js/drag-and-drop-reorder.js") }}"></script>
+  <script src="{{ url_for("accounting.static", filename="js/transaction-form.js") }}"></script>
+{% endblock %}
+
+{% block content %}
+
+<div class="btn-group btn-actions mb-3">
+  <a class="btn btn-primary" role="button" href="{% block back_url %}{% endblock %}">
+    <i class="fa-solid fa-circle-chevron-left"></i>
+    {{ A_("Back") }}
+  </a>
+</div>
+
+<form id="accounting-form" action="{% block action_url %}{% endblock %}" method="post" data-currency-template="{{ currency_template }}" data-entry-template="{{ entry_template }}">
+  {{ form.csrf_token }}
+  {% if "next" in request.args %}
+    <input type="hidden" name="next" value="{{ request.args["next"] }}">
+  {% endif %}
+
+  <div class="form-floating mb-3">
+    <input id="accounting-date" class="form-control {% if form.date.errors %} is-invalid {% endif %}" type="date" name="date" value="{{ "" if form.date.data is none else form.date.data }}" placeholder=" " required="required">
+    <label class="form-label" for="accounting-date">{{ A_("Date") }}</label>
+    <div id="accounting-date-error" class="invalid-feedback">{% if form.date.errors %}{{ form.date.errors[0] }}{% endif %}</div>
+  </div>
+
+  <div class="mb-3">
+    <div id="accounting-currencies" class="form-control accounting-material-text-field accounting-not-empty {% if form.currencies_errors %} is-invalid {% endif %}">
+      <label class="form-label" for="accounting-currencies">{{ A_("Content") }}</label>
+      <div id="accounting-currency-list" class="mt-2">
+        {% block currency_sub_forms %}{% endblock %}
+      </div>
+
+      <div>
+        <button id="accounting-btn-new-currency" class="btn btn-primary" type="button">
+          <i class="fas fa-plus"></i>
+          {{ A_("New") }}
+        </button>
+      </div>
+    </div>
+    <div id="accounting-currencies-error" class="invalid-feedback">{% if form.currencies_errors %}{{ form.currencies_errors[0] }}{% endif %}</div>
+  </div>
+
+  <div class="form-floating mb-3">
+    <textarea id="accounting-note" class="form-control form-control-lg {% if form.note.errors %} is-invalid {% endif %}" name="note" rows="5" placeholder=" ">{{ "" if form.note.data is none else form.note.data }}</textarea>
+    <label class="form-label" for="accounting-note">{{ A_("Note") }}</label>
+    <div id="accounting-note-error" class="invalid-feedback">{% if form.note.errors %}{{ form.note.errors[0] }}{% endif %}</div>
+  </div>
+
+  <div class="d-none d-md-block">
+    <button class="btn btn-primary" type="submit">
+      <i class="fa-solid fa-floppy-disk"></i>
+      {{ A_("Save") }}
+    </button>
+  </div>
+
+  <div class="d-md-none accounting-material-fab">
+    <button class="btn btn-primary" type="submit">
+      <i class="fa-solid fa-floppy-disk"></i>
+    </button>
+  </div>
+</form>
+
+{% include "accounting/transaction/include/entry-form-modal.html" %}
+{% block account_selector_modals %}{% endblock %}
+
+{% endblock %}

src/accounting/templates/accounting/transaction/income/create.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+create.html: The cash income transaction creation form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/income/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Add a New Cash Income Transaction") }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ request.args.get("next") or url_for("accounting.transaction.list") }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.store", txn_type=txn_type) }}{% endblock %}

src/accounting/templates/accounting/transaction/income/detail.html

@@ -0,0 +1,53 @@
+{#
+The Mia! Accounting Flask Project
+detail.html: The account detail
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/transaction/include/detail.html" %}
+
+{% block transaction_currencies %}
+  {% for currency in obj.currencies %}
+    <div class="mb-3">
+      <div class="mb-2 fw-bolder">{{ currency.name }}</div>
+
+      <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
+        <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Content") }}</li>
+        {% for entry in currency.credit %}
+          <li class="list-group-item accounting-transaction-entry">
+            <div class="d-flex justify-content-between">
+              <div>
+                <div class="small">{{ entry.account }}</div>
+                {% if entry.summary is not none %}
+                  <div>{{ entry.summary }}</div>
+                {% endif %}
+              </div>
+              <div>{{ entry.amount|accounting_txn_format_amount }}</div>
+            </div>
+          </li>
+        {% endfor %}
+        <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
+          <div class="d-flex justify-content-between">
+            <div>{{ _("Total") }}</div>
+            <div>{{ currency.debit_total|accounting_txn_format_amount }}</div>
+          </div>
+        </li>
+      </ul>
+    </div>
+  {% endfor %}
+{% endblock %}

src/accounting/templates/accounting/transaction/income/edit.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+edit.html: The cash income transaction edit form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/income/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Editing %(txn)s", txn=txn) }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ url_for("accounting.transaction.detail", txn=txn)|accounting_inherit_next }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.update", txn=txn)|accounting_txn_with_type }}{% endblock %}

src/accounting/templates/accounting/transaction/income/include/form-currency-item.html

@@ -0,0 +1,83 @@
+{#
+The Mia! Accounting Flask Project
+currency-sub-form.html: The currency sub-form in the cash income transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
+    <div class="d-flex justify-content-between mt-2 mb-3">
+      <div class="form-floating accounting-currency-content">
+        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+          {% for currency in accounting_txn_currency_options() %}
+            <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
+          {% endfor %}
+        </select>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
+      </div>
+
+      <div>
+        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+          <i class="fas fa-minus"></i>
+        </button>
+      </div>
+    </div>
+
+    <div class="mb-3">
+      <div id="accounting-currency-{{ currency_index }}-credit" class="form-control accounting-material-text-field accounting-not-empty {% if credit_errors %} is-invalid {% endif %}">
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-credit">{{ A_("Content") }}</label>
+        <ul id="accounting-currency-{{ currency_index }}-credit-list" class="list-group accounting-entry-list">
+          {% for entry_form in credit_forms %}
+            {% with currency_index = currency_index,
+                    entry_type = "credit",
+                    entry_index = loop.index,
+                    only_one_entry_form = debit_forms|length == 1,
+                    entry_id = entry_form.eid.data,
+                    account_code_data = "" if entry_form.account_code.data is none else entry_form.account_code.data,
+                    account_code_error = entry_form.account_code.errors,
+                    account_text = entry_form.account_text,
+                    summary_data = "" if entry_form.summary.data is none else entry_form.summary.data,
+                    summary_errors = entry_form.summary.errors,
+                    amount_data = "" if entry_form.amount.data is none else entry_form.amount.data,
+                    amount_errors = entry_form.amount.errors,
+                    amount_text = entry_form.amount.data|accounting_txn_format_amount,
+                    entry_errors = entry_form.all_errors %}
+              {% include "accounting/transaction/include/form-entry-item.html" %}
+            {% endwith %}
+          {% endfor %}
+        </ul>
+
+        <div class="d-flex justify-content-between mb-2">
+          <div>{{ A_("Total") }}</div>
+          <div><span id="accounting-currency-{{ currency_index }}-credit-total" class="badge rounded-pill bg-primary">{{ credit_total }}</span></div>
+        </div>
+
+        <div>
+          <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-entry-index="new" data-account-modal="#accounting-credit-account-selector-modal" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            <i class="fas fa-plus"></i>
+            {{ A_("New") }}
+          </button>
+        </div>
+      </div>
+      <div id="accounting-currency-{{ currency_index }}-credit-error" class="invalid-feedback">{% if credit_errors %}{{ credit_errors[0] }}{% endif %}</div>
+    </div>
+  </div>
+  <div id="accounting-currency-{{ currency_index }}-error" class="invalid-feedback">{% if currency_errors %}{{ currency_errors[0] }}{% endif %}</div>
+</div>

src/accounting/templates/accounting/transaction/income/include/form.html

@@ -0,0 +1,50 @@
+{#
+The Mia! Accounting Flask Project
+form.html: The cash income transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/include/form.html" %}
+
+{% block currency_sub_forms %}
+  {% if form.currencies %}
+    {% for currency_form in form.currencies %}
+      {% with currency_index = loop.index,
+              only_one_currency_form = form.currencies|length == 1,
+              currency_errors = currency_form.whole_form.errors,
+              currency_code_data = currency_form.code.data,
+              currency_code_errors = currency_form.code.errors,
+              credit_forms = currency_form.credit,
+              credit_errors = currency_form.credit_errors,
+              credit_total = currency_form.form.credit_total|accounting_txn_format_amount %}
+        {% include "accounting/transaction/income/include/form-currency-item.html" %}
+      {% endwith %}
+    {% endfor %}
+  {% else %}
+    {% with currency_index = 1,
+            only_one_currency_form = True,
+            currency_code_data = accounting_txn_default_currency_code(),
+            credit_total = "-" %}
+      {% include "accounting/transaction/income/include/form-currency-item.html" %}
+    {% endwith %}
+  {% endif %}
+{% endblock %}
+
+{% block account_selector_modals %}
+  {% include "accounting/transaction/include/credit-account-modal.html" %}
+{% endblock %}

src/accounting/templates/accounting/transaction/list.html

@@ -0,0 +1,96 @@
+{#
+The Mia! Accounting Flask Project
+list.html: The transaction list
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/18
+#}
+{% extends "accounting/base.html" %}
+
+{% block accounting_scripts %}
+  <script src="{{ url_for("accounting.static", filename="js/material-fab-speed-dial.js") }}"></script>
+{% endblock %}
+
+{% block header %}{% block title %}{% if "q" in request.args %}{{ A_("Search Result for \"%(query)s\"", query=request.args["q"]) }}{% else %}{{ A_("Transaction Management") }}{% endif %}{% endblock %}{% endblock %}
+
+{% block content %}
+
+<div class="btn-group mb-2 d-none d-md-inline-flex">
+  {% if accounting_can_edit() %}
+    <div class="btn-group" role="group">
+      <button type="button" class="btn btn-primary dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">
+        <i class="fa-solid fa-plus"></i>
+        {{ A_("New") }}
+      </button>
+      <ul class="dropdown-menu">
+        <li>
+          <a class="dropdown-item" href="{{ url_for("accounting.transaction.create", txn_type=types.expense)|accounting_append_next }}">
+            {{ A_("Cash Expense") }}</a>
+        </li>
+        <li>
+          <a class="dropdown-item" href="{{ url_for("accounting.transaction.create", txn_type=types.income)|accounting_append_next }}">
+            {{ A_("Cash Income") }}
+          </a>
+        </li>
+        <li>
+          <a class="dropdown-item" href="{{ url_for("accounting.transaction.create", txn_type=types.transfer)|accounting_append_next }}">
+            {{ A_("Transfer") }}
+          </a>
+        </li>
+      </ul>
+    </div>
+  {% endif %}
+  <form class="btn btn-primary d-flex input-group" action="{{ url_for("accounting.transaction.list") }}" method="get" role="search" aria-label="{{ A_("Search for Desktop") }}">
+    <input id="accounting-search-desktop" class="form-control form-control-sm accounting-search-input" type="search" name="q" value="{{ request.args["q"] if "q" in request.args else "" }}" placeholder=" " required="required">
+    <label for="accounting-search-desktop" class="accounting-search-label">
+      <button type="submit">
+        <i class="fa-solid fa-magnifying-glass"></i>
+        {{ A_("Search") }}
+      </button>
+    </label>
+  </form>
+</div>
+
+<div class="btn-group mb-2 d-md-none">
+  <form class="btn btn-primary d-flex input-group" action="{{ url_for("accounting.transaction.list") }}" method="get" role="search" aria-label="{{ A_("Search for Mobile") }}">
+    <input id="accounting-search-mobile" class="form-control form-control-sm accounting-search-input" type="search" name="q" value="{{ request.args["q"] if "q" in request.args else "" }}" placeholder=" " required="required">
+    <label for="accounting-search-mobile" class="accounting-search-label">
+      <button type="submit">
+        <i class="fa-solid fa-magnifying-glass"></i>
+        {{ A_("Search") }}
+      </button>
+    </label>
+  </form>
+</div>
+
+{% include "accounting/transaction/include/add-new-material-fab.html" %}
+
+{% if list %}
+  {% include "accounting/include/pagination.html" %}
+
+  <div class="list-group">
+  {% for item in list %}
+    <a class="list-group-item list-group-item-action" href="{{ url_for("accounting.transaction.detail", txn=item)|accounting_append_next }}">
+      {{ item.date|accounting_txn_format_date }} {{ item }}
+    </a>
+  {% endfor %}
+  </div>
+{% else %}
+  <p>{{ A_("There is no data.") }}</p>
+{% endif %}
+
+{% endblock %}

src/accounting/templates/accounting/transaction/order.html

@@ -0,0 +1,83 @@
+{#
+The Mia! Accounting Flask Project
+order.html: The order of the transactions in a same day
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/base.html" %}
+
+{% block accounting_scripts %}
+  <script src="{{ url_for("accounting.static", filename="js/drag-and-drop-reorder.js") }}"></script>
+  <script src="{{ url_for("accounting.static", filename="js/transaction-order.js") }}"></script>
+{% endblock %}
+
+{% block header %}{% block title %}{{ A_("Transactions on %(date)s", date=date) }}{% endblock %}{% endblock %}
+
+{% block content %}
+
+<div class="btn-group mb-3">
+  <a class="btn btn-primary" href="{{ url_for("accounting.transaction.list")|accounting_or_next }}">
+    <i class="fa-solid fa-circle-chevron-left"></i>
+    {{ A_("Back") }}
+  </a>
+</div>
+
+{% if list|length > 1 and accounting_can_edit() %}
+  <form action="{{ url_for("accounting.transaction.sort", txn_date=date) }}" method="post">
+    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+    {% if "next" in request.args %}
+      <input type="hidden" name="next" value="{{ request.args["next"] }}">
+    {% endif %}
+    <ul id="accounting-order-list" class="list-group mb-3">
+      {% for item in list %}
+        <li class="list-group-item d-flex justify-content-between" data-id="{{ item.id }}">
+          <input id="accounting-order-{{ item.id }}-no" type="hidden" name="{{ item.id }}-no" value="{{ loop.index }}">
+          <div>
+            {{ item }}
+          </div>
+          <i class="fa-solid fa-bars"></i>
+        </li>
+      {% endfor %}
+    </ul>
+
+    <div class="d-none d-md-block">
+      <button class="btn btn-primary" type="submit">
+        <i class="fa-solid fa-floppy-disk"></i>
+        {{ A_("Save") }}
+      </button>
+    </div>
+
+    <div class="d-md-none accounting-material-fab">
+      <button class="btn btn-primary" type="submit">
+        <i class="fa-solid fa-floppy-disk"></i>
+      </button>
+    </div>
+  </form>
+{% elif list %}
+  <ul class="list-group mb-3">
+    {% for item in list %}
+      <li class="list-group-item">
+        {{ item }}
+      </li>
+    {% endfor %}
+  </ul>
+{% else %}
+  <p>{{ A_("There is no data.") }}</p>
+{% endif %}
+
+{% endblock %}

src/accounting/templates/accounting/transaction/transfer/create.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+create.html: The transfer transaction creation form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/transfer/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Add a New Transfer Transaction") }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ request.args.get("next") or url_for("accounting.transaction.list") }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.store", txn_type=txn_type) }}{% endblock %}

src/accounting/templates/accounting/transaction/transfer/detail.html

@@ -0,0 +1,84 @@
+{#
+The Mia! Accounting Flask Project
+detail.html: The account detail
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/26
+#}
+{% extends "accounting/transaction/include/detail.html" %}
+
+{% block transaction_currencies %}
+  {% for currency in obj.currencies %}
+    <div class="mb-3">
+      <div class="mb-2 fw-bolder">{{ currency.name }}</div>
+
+      <div class="row">
+        {# The debit entries #}
+        <div class="col-sm-6 mb-2">
+          <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
+            <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Debit") }}</li>
+            {% for entry in currency.debit %}
+              <li class="list-group-item accounting-transaction-entry">
+                <div class="d-flex justify-content-between">
+                  <div>
+                    <div class="small">{{ entry.account }}</div>
+                    {% if entry.summary is not none %}
+                      <div>{{ entry.summary }}</div>
+                    {% endif %}
+                  </div>
+                  <div>{{ entry.amount|accounting_txn_format_amount }}</div>
+                </div>
+              </li>
+            {% endfor %}
+            <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
+              <div class="d-flex justify-content-between">
+                <div>{{ _("Total") }}</div>
+                <div>{{ currency.debit_total|accounting_txn_format_amount }}</div>
+              </div>
+            </li>
+          </ul>
+        </div>
+
+        {# The credit entries #}
+        <div class="col-sm-6 mb-2">
+          <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
+            <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Credit") }}</li>
+            {% for entry in currency.credit %}
+              <li class="list-group-item accounting-transaction-entry">
+                <div class="d-flex justify-content-between">
+                  <div>
+                    <div class="small">{{ entry.account }}</div>
+                    {% if entry.summary is not none %}
+                      <div>{{ entry.summary }}</div>
+                    {% endif %}
+                  </div>
+                  <div>{{ entry.amount|accounting_txn_format_amount }}</div>
+                </div>
+              </li>
+            {% endfor %}
+            <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
+              <div class="d-flex justify-content-between">
+                <div>{{ _("Total") }}</div>
+                <div>{{ currency.debit_total|accounting_txn_format_amount }}</div>
+              </div>
+            </li>
+          </ul>
+        </div>
+      </div>
+    </div>
+  {% endfor %}
+{% endblock %}

src/accounting/templates/accounting/transaction/transfer/edit.html

@@ -0,0 +1,28 @@
+{#
+The Mia! Accounting Flask Project
+edit.html: The transfer transaction edit form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/transfer/include/form.html" %}
+
+{% block header %}{% block title %}{{ A_("Editing %(txn)s", txn=txn) }}{% endblock %}{% endblock %}
+
+{% block back_url %}{{ url_for("accounting.transaction.detail", txn=txn)|accounting_inherit_next }}{% endblock %}
+
+{% block action_url %}{{ url_for("accounting.transaction.update", txn=txn)|accounting_txn_with_type }}{% endblock %}

src/accounting/templates/accounting/transaction/transfer/include/form-currency-item.html

@@ -0,0 +1,126 @@
+{#
+The Mia! Accounting Flask Project
+currency-sub-form.html: The currency sub-form in the transfer transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
+    <div class="d-flex justify-content-between mt-2 mb-3">
+      <div class="form-floating accounting-currency-content">
+        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+          {% for currency in accounting_txn_currency_options() %}
+            <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
+          {% endfor %}
+        </select>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
+      </div>
+
+      <div>
+        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+          <i class="fas fa-minus"></i>
+        </button>
+      </div>
+    </div>
+
+    <div class="row">
+      {# The debit entries #}
+      <div class="col-sm-6 mb-3">
+        <div id="accounting-currency-{{ currency_index }}-debit" class="form-control accounting-material-text-field accounting-not-empty {% if debit_errors %} is-invalid {% endif %}">
+          <label class="form-label" for="accounting-currency-{{ currency_index }}-debit">{{ A_("Debit") }}</label>
+          <ul id="accounting-currency-{{ currency_index }}-debit-list" class="list-group accounting-entry-list accounting-currency-{{ currency_index }}-entry-list">
+            {% for entry_form in debit_forms %}
+              {% with currency_index = currency_index,
+                      entry_type = "debit",
+                      entry_index = loop.index,
+                      only_one_entry_form = debit_forms|length == 1,
+                      entry_id = entry_form.eid.data,
+                      account_code_data = "" if entry_form.account_code.data is none else entry_form.account_code.data,
+                      account_code_error = entry_form.account_code.errors,
+                      account_text = entry_form.account_text,
+                      summary_data = "" if entry_form.summary.data is none else entry_form.summary.data,
+                      summary_errors = entry_form.summary.errors,
+                      amount_data = "" if entry_form.amount.data is none else entry_form.amount.data,
+                      amount_errors = entry_form.amount.errors,
+                      amount_text = entry_form.amount.data|accounting_txn_format_amount,
+                      entry_errors = entry_form.all_errors %}
+                {% include "accounting/transaction/include/form-entry-item.html" %}
+              {% endwith %}
+            {% endfor %}
+          </ul>
+
+          <div class="d-flex justify-content-between mb-2">
+            <div>{{ A_("Total") }}</div>
+            <div><span id="accounting-currency-{{ currency_index }}-debit-total" class="badge rounded-pill bg-primary">{{ debit_total }}</span></div>
+          </div>
+
+          <div>
+            <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-entry-index="new" data-account-modal="#accounting-debit-account-selector-modal" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+              <i class="fas fa-plus"></i>
+              {{ A_("New") }}
+            </button>
+          </div>
+        </div>
+        <div id="accounting-currency-{{ currency_index }}-debit-error" class="invalid-feedback">{% if debit_errors %}{{ debit_errors[0] }}{% endif %}</div>
+      </div>
+
+      {# The credit entries #}
+      <div class="col-sm-6 mb-3">
+        <div id="accounting-currency-{{ currency_index }}-credit" class="form-control accounting-material-text-field accounting-not-empty {% if credit_errors %} is-invalid {% endif %}">
+          <label class="form-label" for="accounting-currency-{{ currency_index }}-credit">{{ A_("Credit") }}</label>
+          <ul id="accounting-currency-{{ currency_index }}-credit-list" class="list-group accounting-entry-list">
+            {% for entry_form in credit_forms %}
+              {% with currency_index = currency_index,
+                      entry_id = entry_form.eid.data,
+                      entry_type = "credit",
+                      entry_index = loop.index,
+                      only_one_entry_form = debit_forms|length == 1,
+                      account_code_data = "" if entry_form.account_code.data is none else entry_form.account_code.data,
+                      account_code_error = entry_form.account_code.errors,
+                      account_text = entry_form.account_text,
+                      summary_data = "" if entry_form.summary.data is none else entry_form.summary.data,
+                      summary_errors = entry_form.summary.errors,
+                      amount_data = "" if entry_form.amount.data is none else entry_form.amount.data,
+                      amount_errors = entry_form.amount.errors,
+                      amount_text = entry_form.amount.data|accounting_txn_format_amount,
+                      entry_errors = entry_form.all_errors %}
+                {% include "accounting/transaction/include/form-entry-item.html" %}
+              {% endwith %}
+            {% endfor %}
+          </ul>
+
+          <div class="d-flex justify-content-between mb-2">
+            <div>{{ A_("Total") }}</div>
+            <div><span id="accounting-currency-{{ currency_index }}-credit-total" class="badge rounded-pill bg-primary">{{ credit_total }}</span></div>
+          </div>
+
+          <div>
+            <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-entry-index="new" data-account-modal="#accounting-credit-account-selector-modal" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+              <i class="fas fa-plus"></i>
+              {{ A_("New") }}
+            </button>
+          </div>
+        </div>
+        <div id="accounting-currency-{{ currency_index }}-credit-error" class="invalid-feedback">{% if credit_errors %}{{ credit_errors[0] }}{% endif %}</div>
+      </div>
+    </div>
+  </div>
+  <div id="accounting-currency-{{ currency_index }}-error" class="invalid-feedback">{% if currency_errors %}{{ currency_errors[0] }}{% endif %}</div>
+</div>

src/accounting/templates/accounting/transaction/transfer/include/form.html

@@ -0,0 +1,55 @@
+{#
+The Mia! Accounting Flask Project
+form.html: The transfer transaction form
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+{% extends "accounting/transaction/include/form.html" %}
+
+{% block currency_sub_forms %}
+  {% if form.currencies %}
+    {% for currency_form in form.currencies %}
+      {% with currency_index = loop.index,
+              only_one_currency_form = form.currencies|length == 1,
+              currency_errors = currency_form.whole_form.errors,
+              currency_code_data = currency_form.code.data,
+              currency_code_errors = currency_form.code.errors,
+              debit_forms = currency_form.debit,
+              debit_errors = currency_form.debit_errors,
+              debit_total = currency_form.form.debit_total|accounting_txn_format_amount,
+              credit_forms = currency_form.credit,
+              credit_errors = currency_form.credit_errors,
+              credit_total = currency_form.form.credit_total|accounting_txn_format_amount %}
+        {% include "accounting/transaction/transfer/include/form-currency-item.html" %}
+      {% endwith %}
+    {% endfor %}
+  {% else %}
+    {% with currency_index = 1,
+            only_one_currency_form = True,
+            currency_code_data = accounting_txn_default_currency_code(),
+            debit_total = "-",
+            credit_total = "-" %}
+      {% include "accounting/transaction/transfer/include/form-currency-item.html" %}
+    {% endwith %}
+  {% endif %}
+{% endblock %}
+
+{% block account_selector_modals %}
+  {% include "accounting/transaction/include/debit-account-modal.html" %}
+  {% include "accounting/transaction/include/credit-account-modal.html" %}
+{% endblock %}

src/accounting/transaction/__init__.py

@@ -0,0 +1,37 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/18
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The transaction management.
+
+"""
+from flask import Flask, Blueprint
+
+
+def init_app(app: Flask, bp: Blueprint) -> None:
+    """Initialize the application.
+
+    :param app: The Flask application.
+    :param bp: The blueprint of the accounting application.
+    :return: None.
+    """
+    from .converters import TransactionConverter, TransactionTypeConverter, \
+        DateConverter
+    app.url_map.converters["transaction"] = TransactionConverter
+    app.url_map.converters["transactionType"] = TransactionTypeConverter
+    app.url_map.converters["date"] = DateConverter
+
+    from .views import bp as transaction_bp
+    bp.register_blueprint(transaction_bp, url_prefix="/transactions")

src/accounting/transaction/converters.py

@@ -0,0 +1,100 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/19
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The path converters for the transaction management.
+
+"""
+from datetime import date
+
+from flask import abort
+from werkzeug.routing import BaseConverter
+
+from accounting import db
+from accounting.models import Transaction
+from accounting.transaction.dispatcher import TransactionType, \
+    TXN_TYPE_DICT
+
+
+class TransactionConverter(BaseConverter):
+    """The transaction converter to convert the transaction ID from and to the
+    corresponding transaction in the routes."""
+
+    def to_python(self, value: str) -> Transaction:
+        """Converts a transaction ID to a transaction.
+
+        :param value: The transaction ID.
+        :return: The corresponding transaction.
+        """
+        transaction: Transaction | None = db.session.get(Transaction, value)
+        if transaction is None:
+            abort(404)
+        return transaction
+
+    def to_url(self, value: Transaction) -> str:
+        """Converts a transaction to its ID.
+
+        :param value: The transaction.
+        :return: The ID.
+        """
+        return str(value.id)
+
+
+class TransactionTypeConverter(BaseConverter):
+    """The transaction converter to convert the transaction type ID from and to
+    the corresponding transaction type in the routes."""
+
+    def to_python(self, value: str) -> TransactionType:
+        """Converts a transaction ID to a transaction.
+
+        :param value: The transaction ID.
+        :return: The corresponding transaction.
+        """
+        txn_type: TransactionType | None = TXN_TYPE_DICT.get(value)
+        if txn_type is None:
+            abort(404)
+        return txn_type
+
+    def to_url(self, value: TransactionType) -> str:
+        """Converts a transaction type to its ID.
+
+        :param value: The transaction type.
+        :return: The ID.
+        """
+        return str(value.ID)
+
+
+class DateConverter(BaseConverter):
+    """The date converter to convert the ISO date from and to the
+    corresponding date in the routes."""
+
+    def to_python(self, value: str) -> date:
+        """Converts an ISO date to a date.
+
+        :param value: The ISO date.
+        :return: The corresponding date.
+        """
+        try:
+            return date.fromisoformat(value)
+        except ValueError:
+            abort(404)
+
+    def to_url(self, value: date) -> str:
+        """Converts a date to its ISO date.
+
+        :param value: The date.
+        :return: The ISO date.
+        """
+        return value.isoformat()

src/accounting/transaction/dispatcher.py

@@ -0,0 +1,344 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/19
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The transaction type dispatcher.
+
+"""
+import typing as t
+from abc import ABC, abstractmethod
+
+from flask import render_template, request, abort
+from flask_wtf import FlaskForm
+
+from accounting.models import Transaction
+from .forms import TransactionForm, IncomeTransactionForm, \
+    ExpenseTransactionForm, TransferTransactionForm
+from .template import default_currency_code
+
+
+class TransactionType(ABC):
+    """An abstract transaction type."""
+    ID: str = ""
+    """The transaction type ID."""
+    CHECK_ORDER: int = -1
+    """The order when checking the transaction type."""
+
+    @property
+    @abstractmethod
+    def form(self) -> t.Type[TransactionForm]:
+        """Returns the form class.
+
+        :return: The form class.
+        """
+
+    @abstractmethod
+    def render_create_template(self, form: FlaskForm) -> str:
+        """Renders the template for the form to create a transaction.
+
+        :param form: The transaction form.
+        :return: the form to create a transaction.
+        """
+
+    @abstractmethod
+    def render_detail_template(self, txn: Transaction) -> str:
+        """Renders the template for the detail page.
+
+        :param txn: The transaction.
+        :return: the detail page.
+        """
+
+    @abstractmethod
+    def render_edit_template(self, txn: Transaction, form: FlaskForm) -> str:
+        """Renders the template for the form to edit a transaction.
+
+        :param txn: The transaction.
+        :param form: The form.
+        :return: the form to edit a transaction.
+        """
+
+    @abstractmethod
+    def is_my_type(self, txn: Transaction) -> bool:
+        """Checks and returns whether the transaction belongs to the type.
+
+        :param txn: The transaction.
+        :return: True if the transaction belongs to the type, or False
+            otherwise.
+        """
+
+    @property
+    def _entry_template(self) -> str:
+        """Renders and returns the template for the journal entry sub-form.
+
+        :return: The template for the journal entry sub-form.
+        """
+        return render_template(
+            "accounting/transaction/include/form-entry-item.html",
+            currency_index="CURRENCY_INDEX",
+            entry_type="ENTRY_TYPE",
+            entry_index="ENTRY_INDEX")
+
+
+class IncomeTransaction(TransactionType):
+    """An income transaction."""
+    ID: str = "income"
+    """The transaction type ID."""
+    CHECK_ORDER: int = 2
+    """The order when checking the transaction type."""
+
+    @property
+    def form(self) -> t.Type[TransactionForm]:
+        """Returns the form class.
+
+        :return: The form class.
+        """
+        return IncomeTransactionForm
+
+    def render_create_template(self, form: IncomeTransactionForm) -> str:
+        """Renders the template for the form to create a transaction.
+
+        :param form: The transaction form.
+        :return: the form to create a transaction.
+        """
+        return render_template("accounting/transaction/income/create.html",
+                               form=form, txn_type=self,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def render_detail_template(self, txn: Transaction) -> str:
+        """Renders the template for the detail page.
+
+        :param txn: The transaction.
+        :return: the detail page.
+        """
+        return render_template("accounting/transaction/income/detail.html",
+                               obj=txn)
+
+    def render_edit_template(self, txn: Transaction,
+                             form: IncomeTransactionForm) -> str:
+        """Renders the template for the form to edit a transaction.
+
+        :param txn: The transaction.
+        :param form: The form.
+        :return: the form to edit a transaction.
+        """
+        return render_template("accounting/transaction/income/edit.html",
+                               txn=txn, form=form,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def is_my_type(self, txn: Transaction) -> bool:
+        """Checks and returns whether the transaction belongs to the type.
+
+        :param txn: The transaction.
+        :return: True if the transaction belongs to the type, or False
+            otherwise.
+        """
+        return txn.is_cash_income
+
+    @property
+    def __currency_template(self) -> str:
+        """Renders and returns the template for the currency sub-form.
+
+        :return: The template for the currency sub-form.
+        """
+        return render_template(
+            "accounting/transaction/income/include/form-currency-item.html",
+            currency_index="CURRENCY_INDEX",
+            currency_code_data=default_currency_code(),
+            credit_total="-")
+
+
+class ExpenseTransaction(TransactionType):
+    """An expense transaction."""
+    ID: str = "expense"
+    """The transaction type ID."""
+    CHECK_ORDER: int = 1
+    """The order when checking the transaction type."""
+
+    @property
+    def form(self) -> t.Type[TransactionForm]:
+        """Returns the form class.
+
+        :return: The form class.
+        """
+        return ExpenseTransactionForm
+
+    def render_create_template(self, form: ExpenseTransactionForm) -> str:
+        """Renders the template for the form to create a transaction.
+
+        :param form: The transaction form.
+        :return: the form to create a transaction.
+        """
+        return render_template("accounting/transaction/expense/create.html",
+                               form=form, txn_type=self,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def render_detail_template(self, txn: Transaction) -> str:
+        """Renders the template for the detail page.
+
+        :param txn: The transaction.
+        :return: the detail page.
+        """
+        return render_template("accounting/transaction/expense/detail.html",
+                               obj=txn)
+
+    def render_edit_template(self, txn: Transaction,
+                             form: ExpenseTransactionForm) -> str:
+        """Renders the template for the form to edit a transaction.
+
+        :param txn: The transaction.
+        :param form: The form.
+        :return: the form to edit a transaction.
+        """
+        return render_template("accounting/transaction/expense/edit.html",
+                               txn=txn, form=form,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def is_my_type(self, txn: Transaction) -> bool:
+        """Checks and returns whether the transaction belongs to the type.
+
+        :param txn: The transaction.
+        :return: True if the transaction belongs to the type, or False
+            otherwise.
+        """
+        return txn.is_cash_expense
+
+    @property
+    def __currency_template(self) -> str:
+        """Renders and returns the template for the currency sub-form.
+
+        :return: The template for the currency sub-form.
+        """
+        return render_template(
+            "accounting/transaction/expense/include/form-currency-item.html",
+            currency_index="CURRENCY_INDEX",
+            currency_code_data=default_currency_code(),
+            debit_total="-")
+
+
+class TransferTransaction(TransactionType):
+    """A transfer transaction."""
+    ID: str = "transfer"
+    """The transaction type ID."""
+    CHECK_ORDER: int = 3
+    """The order when checking the transaction type."""
+
+    @property
+    def form(self) -> t.Type[TransactionForm]:
+        """Returns the form class.
+
+        :return: The form class.
+        """
+        return TransferTransactionForm
+
+    def render_create_template(self, form: TransferTransactionForm) -> str:
+        """Renders the template for the form to create a transaction.
+
+        :param form: The transaction form.
+        :return: the form to create a transaction.
+        """
+        return render_template("accounting/transaction/transfer/create.html",
+                               form=form, txn_type=self,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def render_detail_template(self, txn: Transaction) -> str:
+        """Renders the template for the detail page.
+
+        :param txn: The transaction.
+        :return: the detail page.
+        """
+        return render_template("accounting/transaction/transfer/detail.html",
+                               obj=txn)
+
+    def render_edit_template(self, txn: Transaction,
+                             form: TransferTransactionForm) -> str:
+        """Renders the template for the form to edit a transaction.
+
+        :param txn: The transaction.
+        :param form: The form.
+        :return: the form to edit a transaction.
+        """
+        return render_template("accounting/transaction/transfer/edit.html",
+                               txn=txn, form=form,
+                               currency_template=self.__currency_template,
+                               entry_template=self._entry_template)
+
+    def is_my_type(self, txn: Transaction) -> bool:
+        """Checks and returns whether the transaction belongs to the type.
+
+        :param txn: The transaction.
+        :return: True if the transaction belongs to the type, or False
+            otherwise.
+        """
+        return True
+
+    @property
+    def __currency_template(self) -> str:
+        """Renders and returns the template for the currency sub-form.
+
+        :return: The template for the currency sub-form.
+        """
+        return render_template(
+            "accounting/transaction/transfer/include/form-currency-item.html",
+            currency_index="CURRENCY_INDEX",
+            currency_code_data=default_currency_code(),
+            debit_total="-", credit_total="-")
+
+
+class TransactionTypes:
+    """The transaction types, as object properties."""
+
+    def __init__(self, income: IncomeTransaction, expense: ExpenseTransaction,
+                 transfer: TransferTransaction):
+        """Constructs the transaction types as object properties.
+
+        :param income: The income transaction type.
+        :param expense: The expense transaction type.
+        :param transfer: The transfer transaction type.
+        """
+        self.income: IncomeTransaction = income
+        self.expense: ExpenseTransaction = expense
+        self.transfer: TransferTransaction = transfer
+
+
+TXN_TYPE_DICT: dict[str, TransactionType] \
+    = {x.ID: x() for x in {IncomeTransaction,
+                           ExpenseTransaction,
+                           TransferTransaction}}
+"""The transaction types, as a dictionary."""
+TXN_TYPE_OBJ: TransactionTypes = TransactionTypes(**TXN_TYPE_DICT)
+"""The transaction types, as an object."""
+
+
+def get_txn_type(txn: Transaction) -> TransactionType:
+    """Returns the transaction type that may be specified in the "as" query
+    parameter.  If it is not specified, check the transaction type from the
+    transaction.
+
+    :param txn: The transaction.
+    :return: None.
+    """
+    if "as" in request.args:
+        if request.args["as"] not in TXN_TYPE_DICT:
+            abort(404)
+        return TXN_TYPE_DICT[request.args["as"]]
+    for txn_type in sorted(TXN_TYPE_DICT.values(),
+                           key=lambda x: x.CHECK_ORDER):
+        if txn_type.is_my_type(txn):
+            return txn_type

src/accounting/transaction/forms.py

@@ -0,0 +1,832 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/18
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The forms for the transaction management.
+
+"""
+from __future__ import annotations
+
+import re
+import typing as t
+from abc import ABC, abstractmethod
+from datetime import date
+from decimal import Decimal
+
+import sqlalchemy as sa
+from flask import request
+from flask_babel import LazyString
+from flask_wtf import FlaskForm
+from wtforms import DateField, StringField, FieldList, FormField, \
+    IntegerField, TextAreaField, DecimalField, BooleanField
+from wtforms.validators import DataRequired, ValidationError
+
+from accounting import db
+from accounting.locale import lazy_gettext
+from accounting.models import Transaction, Account, JournalEntry, \
+    TransactionCurrency, Currency
+from accounting.utils.random_id import new_id
+from accounting.utils.strip_text import strip_text, strip_multiline_text
+from accounting.utils.user import get_current_user_pk
+
+MISSING_CURRENCY: LazyString = lazy_gettext("Please select the currency.")
+"""The error message when the currency code is empty."""
+MISSING_ACCOUNT: LazyString = lazy_gettext("Please select the account.")
+"""The error message when the account code is empty."""
+
+
+class NeedSomeCurrencies:
+    """The validator to check if there is any currency sub-form."""
+
+    def __call__(self, form: CurrencyForm, field: FieldList) \
+            -> None:
+        if len(field) == 0:
+            raise ValidationError(lazy_gettext(
+                "Please add some currencies."))
+
+
+class CurrencyExists:
+    """The validator to check if the account exists."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if db.session.get(Currency, field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The currency does not exist."))
+
+
+class NeedSomeJournalEntries:
+    """The validator to check if there is any journal entry sub-form."""
+
+    def __call__(self, form: TransferCurrencyForm, field: FieldList) \
+            -> None:
+        if len(field) == 0:
+            raise ValidationError(lazy_gettext(
+                "Please add some journal entries."))
+
+
+class AccountExists:
+    """The validator to check if the account exists."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if Account.find_by_code(field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The account does not exist."))
+
+
+class PositiveAmount:
+    """The validator to check if the amount is positive."""
+
+    def __call__(self, form: FlaskForm, field: DecimalField) -> None:
+        if field.data is None:
+            return
+        if field.data <= 0:
+            raise ValidationError(lazy_gettext(
+                "Please fill in a positive amount."))
+
+
+class IsDebitAccount:
+    """The validator to check if the account is for debit journal entries."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if re.match(r"^(?:[1235689]|7[5678])", field.data) \
+                and not field.data.startswith("3351-") \
+                and not field.data.startswith("3353-"):
+            return
+        raise ValidationError(lazy_gettext(
+            "This account is not for debit entries."))
+
+
+class JournalEntryForm(FlaskForm):
+    """The base form to create or edit a journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    account_code = StringField()
+    """The account code."""
+    amount = DecimalField()
+    """The amount."""
+
+    @property
+    def account_text(self) -> str:
+        """Returns the text representation of the account.
+
+        :return: The text representation of the account.
+        """
+        if self.account_code.data is None:
+            return ""
+        account: Account | None = Account.find_by_code(self.account_code.data)
+        if account is None:
+            return ""
+        return str(account)
+
+    @property
+    def all_errors(self) -> list[str | LazyString]:
+        """Returns all the errors of the form.
+
+        :return: All the errors of the form.
+        """
+        all_errors: list[str | LazyString] = []
+        for key in self.errors:
+            if key != "csrf_token":
+                all_errors.extend(self.errors[key])
+        return all_errors
+
+
+class DebitEntryForm(JournalEntryForm):
+    """The form to create or edit a debit journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    account_code = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(MISSING_ACCOUNT),
+                    AccountExists(),
+                    IsDebitAccount()])
+    """The account code."""
+    summary = StringField(filters=[strip_text])
+    """The summary."""
+    amount = DecimalField(validators=[PositiveAmount()])
+    """The amount."""
+
+    def populate_obj(self, obj: JournalEntry) -> None:
+        """Populates the form data into a journal entry object.
+
+        :param obj: The journal entry object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        if is_new:
+            obj.id = new_id(JournalEntry)
+        obj.account_id = Account.find_by_code(self.account_code.data).id
+        obj.summary = self.summary.data
+        obj.is_debit = True
+        obj.amount = self.amount.data
+        if is_new:
+            current_user_pk: int = get_current_user_pk()
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk
+
+
+class IsCreditAccount:
+    """The validator to check if the account is for credit journal entries."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if re.match(r"^(?:[123489]|7[1234])", field.data) \
+                and not field.data.startswith("3351-") \
+                and not field.data.startswith("3353-"):
+            return
+        raise ValidationError(lazy_gettext(
+            "This account is not for credit entries."))
+
+
+class CreditEntryForm(JournalEntryForm):
+    """The form to create or edit a credit journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    account_code = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(MISSING_ACCOUNT),
+                    AccountExists(),
+                    IsCreditAccount()])
+    """The account code."""
+    summary = StringField(filters=[strip_text])
+    """The summary."""
+    amount = DecimalField(validators=[PositiveAmount()])
+    """The amount."""
+
+    def populate_obj(self, obj: JournalEntry) -> None:
+        """Populates the form data into a journal entry object.
+
+        :param obj: The journal entry object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        if is_new:
+            obj.id = new_id(JournalEntry)
+        obj.account_id = Account.find_by_code(self.account_code.data).id
+        obj.summary = self.summary.data
+        obj.is_debit = False
+        obj.amount = self.amount.data
+        if is_new:
+            current_user_pk: int = get_current_user_pk()
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk
+
+
+class CurrencyForm(FlaskForm):
+    """The form to create or edit a currency in a transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField()
+    """The currency code."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+
+class TransactionForm(FlaskForm):
+    """The base form to create or edit a transaction."""
+    date = DateField()
+    """The date."""
+    currencies = FieldList(FormField(CurrencyForm))
+    """The journal entries categorized by their currencies."""
+    note = TextAreaField()
+    """The note."""
+
+    def __init__(self, *args, **kwargs):
+        """Constructs a base transaction form.
+
+        :param args: The arguments.
+        :param kwargs: The keyword arguments.
+        """
+        super().__init__(*args, **kwargs)
+        self.is_modified: bool = False
+        """Whether the transaction is modified during populate_obj()."""
+        self.collector: t.Type[JournalEntryCollector] = JournalEntryCollector
+        """The journal entry collector.  The default is the base abstract
+        collector only to provide the correct type.  The subclass forms should
+        provide their own collectors."""
+        self.__in_use_account_id: set[int] | None = None
+        """The ID of the accounts that are in use."""
+
+    def populate_obj(self, obj: Transaction) -> None:
+        """Populates the form data into a transaction object.
+
+        :param obj: The transaction object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        if is_new:
+            obj.id = new_id(Transaction)
+        self.__set_date(obj, self.date.data)
+        obj.note = self.note.data
+
+        entries: list[JournalEntry] = obj.entries
+        collector_cls: t.Type[JournalEntryCollector] = self.collector
+        collector: collector_cls = collector_cls(self, obj.id, entries,
+                                                 obj.currencies)
+        collector.collect()
+
+        to_delete: set[int] = {x.id for x in entries
+                               if x.id not in collector.to_keep}
+        if len(to_delete) > 0:
+            JournalEntry.query.filter(JournalEntry.id.in_(to_delete)).delete()
+            self.is_modified = True
+
+        if is_new or db.session.is_modified(obj):
+            self.is_modified = True
+
+        if is_new:
+            current_user_pk: int = get_current_user_pk()
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk
+
+    @staticmethod
+    def __set_date(obj: Transaction, new_date: date) -> None:
+        """Sets the transaction date and number.
+
+        :param obj: The transaction object.
+        :param new_date: The new date.
+        :return: None.
+        """
+        if obj.date is None or obj.date != new_date:
+            if obj.date is not None:
+                sort_transactions_in(obj.date, obj.id)
+            sort_transactions_in(new_date, obj.id)
+            count: int = Transaction.query\
+                .filter(Transaction.date == new_date).count()
+            obj.date = new_date
+            obj.no = count + 1
+
+    @property
+    def debit_account_options(self) -> list[Account]:
+        """The selectable debit accounts.
+
+        :return: The selectable debit accounts.
+        """
+        accounts: list[Account] = Account.debit()
+        in_use: set[int] = self.__get_in_use_account_id()
+        for account in accounts:
+            account.is_in_use = account.id in in_use
+        return accounts
+
+    @property
+    def credit_account_options(self) -> list[Account]:
+        """The selectable credit accounts.
+
+        :return: The selectable credit accounts.
+        """
+        accounts: list[Account] = Account.credit()
+        in_use: set[int] = self.__get_in_use_account_id()
+        for account in accounts:
+            account.is_in_use = account.id in in_use
+        return accounts
+
+    def __get_in_use_account_id(self) -> set[int]:
+        """Returns the ID of the accounts that are in use.
+
+        :return: The ID of the accounts that are in use.
+        """
+        if self.__in_use_account_id is None:
+            self.__in_use_account_id = set(db.session.scalars(
+                sa.select(JournalEntry.account_id)
+                .group_by(JournalEntry.account_id)).all())
+        return self.__in_use_account_id
+
+    @property
+    def currencies_errors(self) -> list[str | LazyString]:
+        """Returns the currency errors, without the errors in their sub-forms.
+
+        :return:
+        """
+        return [x for x in self.currencies.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+T = t.TypeVar("T", bound=TransactionForm)
+"""A transaction form variant."""
+
+
+class JournalEntryCollector(t.Generic[T], ABC):
+    """The journal entry collector."""
+
+    def __init__(self, form: T, txn_id: int, entries: list[JournalEntry],
+                 currencies: list[TransactionCurrency]):
+        """Constructs the journal entry collector.
+
+        :param form: The transaction form.
+        :param txn_id: The transaction ID.
+        :param entries: The existing journal entries.
+        :param currencies: The currencies in the transaction.
+        """
+        self.form: T = form
+        """The transaction form."""
+        self.entries: list[JournalEntry] = entries
+        """The existing journal entries."""
+        self.txn_id: int = txn_id
+        """The transaction ID."""
+        self.__entries_by_id: dict[int, JournalEntry] \
+            = {x.id: x for x in entries}
+        """A dictionary from the entry ID to their entries."""
+        self.__no_by_id: dict[int, int] = {x.id: x.no for x in entries}
+        """A dictionary from the entry number to their entries."""
+        self.__currencies: list[TransactionCurrency] = currencies
+        """The currencies in the transaction."""
+        self._debit_no: int = 1
+        """The number index for the debit entries."""
+        self._credit_no: int = 1
+        """The number index for the credit entries."""
+        self.to_keep: set[int] = set()
+        """The ID of the existing journal entries to keep."""
+
+    @abstractmethod
+    def collect(self) -> set[int]:
+        """Collects the journal entries.
+
+        :return: The ID of the journal entries to keep.
+        """
+
+    def _add_entry(self, form: JournalEntryForm, currency_code: str, no: int) \
+            -> None:
+        """Composes a journal entry from the form.
+
+        :param form: The journal entry form.
+        :param currency_code: The code of the currency.
+        :param no: The number of the entry.
+        :return: None.
+        """
+        entry: JournalEntry | None = self.__entries_by_id.get(form.eid.data)
+        if entry is not None:
+            self.to_keep.add(entry.id)
+            entry.currency_code = currency_code
+            form.populate_obj(entry)
+            entry.no = no
+            if db.session.is_modified(entry):
+                self.form.is_modified = True
+        else:
+            entry = JournalEntry()
+            entry.transaction_id = self.txn_id
+            entry.currency_code = currency_code
+            form.populate_obj(entry)
+            entry.no = no
+            db.session.add(entry)
+            self.form.is_modified = True
+
+    def _make_cash_entry(self, forms: list[JournalEntryForm], is_debit: bool,
+                         currency_code: str, no: int) -> None:
+        """Composes the cash journal entry at the other side of the cash
+        transaction.
+
+        :param forms: The journal entry forms in the same currency.
+        :param is_debit: True for a cash income transaction, or False for a
+            cash expense transaction.
+        :param currency_code: The code of the currency.
+        :param no: The number of the entry.
+        :return: None.
+        """
+        candidates: list[JournalEntry] = [x for x in self.entries
+                                          if x.is_debit == is_debit
+                                          and x.currency_code == currency_code]
+        entry: JournalEntry
+        if len(candidates) > 0:
+            candidates.sort(key=lambda x: x.no)
+            entry = candidates[0]
+            self.to_keep.add(entry.id)
+            entry.account_id = Account.cash().id
+            entry.summary = None
+            entry.amount = sum([x.amount.data for x in forms])
+            entry.no = no
+            if db.session.is_modified(entry):
+                self.form.is_modified = True
+        else:
+            entry = JournalEntry()
+            entry.id = new_id(JournalEntry)
+            entry.transaction_id = self.txn_id
+            entry.is_debit = is_debit
+            entry.currency_code = currency_code
+            entry.account_id = Account.cash().id
+            entry.summary = None
+            entry.amount = sum([x.amount.data for x in forms])
+            entry.no = no
+            db.session.add(entry)
+            self.form.is_modified = True
+
+    def _sort_entry_forms(self, forms: list[JournalEntryForm]) -> None:
+        """Sorts the journal entry forms.
+
+        :param forms: The journal entry forms.
+        :return: None.
+        """
+        missing_no: int = 100 if len(self.__no_by_id) == 0 \
+            else max(self.__no_by_id.values()) + 100
+        ord_by_form: dict[JournalEntryForm, int] \
+            = {forms[i]: i for i in range(len(forms))}
+        recv_no: set[int] = {x.no.data for x in forms if x.no.data is not None}
+        missing_recv_no: int = 100 if len(recv_no) == 0 else max(recv_no) + 100
+        forms.sort(key=lambda x: (x.no.data or missing_recv_no,
+                                  missing_no if x.eid.data is None else
+                                  self.__no_by_id.get(x.eid.data, missing_no),
+                                  ord_by_form.get(x)))
+
+    def _sort_currency_forms(self, forms: list[CurrencyForm]) -> None:
+        """Sorts the currency forms.
+
+        :param forms: The currency forms.
+        :return: None.
+        """
+        missing_no: int = len(self.__currencies) + 100
+        no_by_code: dict[str, int] = {self.__currencies[i].code: i
+                                      for i in range(len(self.__currencies))}
+        ord_by_form: dict[CurrencyForm, int] \
+            = {forms[i]: i for i in range(len(forms))}
+        recv_no: set[int] = {x.no.data for x in forms if x.no.data is not None}
+        missing_recv_no: int = 100 if len(recv_no) == 0 else max(recv_no) + 100
+        forms.sort(key=lambda x: (x.no.data or missing_recv_no,
+                                  no_by_code.get(x.code.data, missing_no),
+                                  ord_by_form.get(x)))
+
+
+class IncomeCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a cash income transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(MISSING_CURRENCY),
+                    CurrencyExists()])
+    """The currency code."""
+    credit = FieldList(FormField(CreditEntryForm),
+                       validators=[NeedSomeJournalEntries()])
+    """The credit entries."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def credit_total(self) -> Decimal:
+        """Returns the total amount of the credit journal entries.
+
+        :return: The total amount of the credit journal entries.
+        """
+        return sum([x.amount.data for x in self.credit
+                    if x.amount.data is not None])
+
+    @property
+    def credit_errors(self) -> list[str | LazyString]:
+        """Returns the credit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.credit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+class IncomeTransactionForm(TransactionForm):
+    """The form to create or edit a cash income transaction."""
+    date = DateField(default=date.today())
+    """The date."""
+    currencies = FieldList(FormField(IncomeCurrencyForm), name="currency",
+                           validators=[NeedSomeCurrencies()])
+    """The journal entries categorized by their currencies."""
+    note = TextAreaField(filters=[strip_multiline_text])
+    """The note."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        class Collector(JournalEntryCollector[IncomeTransactionForm]):
+            """The journal entry collector for the cash income transactions."""
+
+            def collect(self) -> None:
+                currencies: list[IncomeCurrencyForm] \
+                    = [x.form for x in self.form.currencies]
+                self._sort_currency_forms(currencies)
+                for currency in currencies:
+                    # The debit cash entry
+                    self._make_cash_entry(list(currency.credit), True,
+                                          currency.code.data, self._debit_no)
+                    self._debit_no = self._debit_no + 1
+
+                    # The credit forms
+                    credit_forms: list[CreditEntryForm] \
+                        = [x.form for x in currency.credit]
+                    self._sort_entry_forms(credit_forms)
+                    for credit_form in credit_forms:
+                        self._add_entry(credit_form, currency.code.data,
+                                        self._credit_no)
+                        self._credit_no = self._credit_no + 1
+
+        self.collector = Collector
+
+
+class ExpenseCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a cash expense transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(MISSING_CURRENCY),
+                    CurrencyExists()])
+    """The currency code."""
+    debit = FieldList(FormField(DebitEntryForm),
+                      validators=[NeedSomeJournalEntries()])
+    """The debit entries."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def debit_total(self) -> Decimal:
+        """Returns the total amount of the debit journal entries.
+
+        :return: The total amount of the debit journal entries.
+        """
+        return sum([x.amount.data for x in self.debit
+                    if x.amount.data is not None])
+
+    @property
+    def debit_errors(self) -> list[str | LazyString]:
+        """Returns the debit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.debit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+class ExpenseTransactionForm(TransactionForm):
+    """The form to create or edit a cash expense transaction."""
+    date = DateField(default=date.today())
+    """The date."""
+    currencies = FieldList(FormField(ExpenseCurrencyForm), name="currency",
+                           validators=[NeedSomeCurrencies()])
+    """The journal entries categorized by their currencies."""
+    note = TextAreaField(filters=[strip_multiline_text])
+    """The note."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        class Collector(JournalEntryCollector[ExpenseTransactionForm]):
+            """The journal entry collector for the cash expense
+            transactions."""
+
+            def collect(self) -> None:
+                currencies: list[ExpenseCurrencyForm] \
+                    = [x.form for x in self.form.currencies]
+                self._sort_currency_forms(currencies)
+                for currency in currencies:
+                    # The debit forms
+                    debit_forms: list[DebitEntryForm] \
+                        = [x.form for x in currency.debit]
+                    self._sort_entry_forms(debit_forms)
+                    for debit_form in debit_forms:
+                        self._add_entry(debit_form, currency.code.data,
+                                        self._debit_no)
+                        self._debit_no = self._debit_no + 1
+
+                    # The credit forms
+                    self._make_cash_entry(list(currency.debit), False,
+                                          currency.code.data, self._credit_no)
+                    self._credit_no = self._credit_no + 1
+
+        self.collector = Collector
+
+
+class TransferCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a transfer transaction."""
+
+    class IsBalanced:
+        """The validator to check that the total amount of the debit and credit
+        entries are equal."""
+        def __call__(self, form: TransferCurrencyForm, field: BooleanField)\
+                -> None:
+            if len(form.debit) == 0 or len(form.credit) == 0:
+                return
+            if form.debit_total != form.credit_total:
+                raise ValidationError(lazy_gettext(
+                    "The totals of the debit and credit amounts do not"
+                    " match."))
+
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(MISSING_CURRENCY),
+                    CurrencyExists()])
+    """The currency code."""
+    debit = FieldList(FormField(DebitEntryForm),
+                      validators=[NeedSomeJournalEntries()])
+    """The debit entries."""
+    credit = FieldList(FormField(CreditEntryForm),
+                       validators=[NeedSomeJournalEntries()])
+    """The credit entries."""
+    whole_form = BooleanField(validators=[IsBalanced()])
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def debit_total(self) -> Decimal:
+        """Returns the total amount of the debit journal entries.
+
+        :return: The total amount of the debit journal entries.
+        """
+        return sum([x.amount.data for x in self.debit
+                    if x.amount.data is not None])
+
+    @property
+    def credit_total(self) -> Decimal:
+        """Returns the total amount of the credit journal entries.
+
+        :return: The total amount of the credit journal entries.
+        """
+        return sum([x.amount.data for x in self.credit
+                    if x.amount.data is not None])
+
+    @property
+    def debit_errors(self) -> list[str | LazyString]:
+        """Returns the debit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.debit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+    @property
+    def credit_errors(self) -> list[str | LazyString]:
+        """Returns the credit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.credit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+class TransferTransactionForm(TransactionForm):
+    """The form to create or edit a transfer transaction."""
+    date = DateField(default=date.today())
+    """The date."""
+    currencies = FieldList(FormField(TransferCurrencyForm), name="currency",
+                           validators=[NeedSomeCurrencies()])
+    """The journal entries categorized by their currencies."""
+    note = TextAreaField(filters=[strip_multiline_text])
+    """The note."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        class Collector(JournalEntryCollector[TransferTransactionForm]):
+            """The journal entry collector for the transfer transactions."""
+
+            def collect(self) -> None:
+                currencies: list[TransferCurrencyForm] \
+                    = [x.form for x in self.form.currencies]
+                self._sort_currency_forms(currencies)
+                for currency in currencies:
+                    # The debit forms
+                    debit_forms: list[DebitEntryForm] \
+                        = [x.form for x in currency.debit]
+                    self._sort_entry_forms(debit_forms)
+                    for debit_form in debit_forms:
+                        self._add_entry(debit_form, currency.code.data,
+                                        self._debit_no)
+                        self._debit_no = self._debit_no + 1
+
+                    # The credit forms
+                    credit_forms: list[CreditEntryForm] \
+                        = [x.form for x in currency.credit]
+                    self._sort_entry_forms(credit_forms)
+                    for credit_form in credit_forms:
+                        self._add_entry(credit_form, currency.code.data,
+                                        self._credit_no)
+                        self._credit_no = self._credit_no + 1
+
+        self.collector = Collector
+
+
+def sort_transactions_in(txn_date: date, exclude: int) -> None:
+    """Sorts the transactions under a date after changing the date or deleting
+    a transaction.
+
+    :param txn_date: The date of the transaction.
+    :param exclude: The transaction ID to exclude.
+    :return: None.
+    """
+    transactions: list[Transaction] = Transaction.query\
+        .filter(Transaction.date == txn_date,
+                Transaction.id != exclude)\
+        .order_by(Transaction.no).all()
+    for i in range(len(transactions)):
+        if transactions[i].no != i + 1:
+            transactions[i].no = i + 1
+
+
+class TransactionReorderForm:
+    """The form to reorder the transactions."""
+
+    def __init__(self, txn_date: date):
+        """Constructs the form to reorder the transactions in a day.
+
+        :param txn_date: The date.
+        """
+        self.date: date = txn_date
+        self.is_modified: bool = False
+
+    def save_order(self) -> None:
+        """Saves the order of the account.
+
+        :return:
+        """
+        transactions: list[Transaction] = Transaction.query\
+            .filter(Transaction.date == self.date).all()
+
+        # Collects the specified order.
+        orders: dict[Transaction, int] = {}
+        for txn in transactions:
+            if f"{txn.id}-no" in request.form:
+                try:
+                    orders[txn] = int(request.form[f"{txn.id}-no"])
+                except ValueError:
+                    pass
+
+        # Missing and invalid orders are appended to the end.
+        missing: list[Transaction] \
+            = [x for x in transactions if x not in orders]
+        if len(missing) > 0:
+            next_no: int = 1 if len(orders) == 0 else max(orders.values()) + 1
+            for txn in missing:
+                orders[txn] = next_no
+
+        # Sort by the specified order first, and their original order.
+        transactions.sort(key=lambda x: (orders[x], x.no))
+
+        # Update the orders.
+        with db.session.no_autoflush:
+            for i in range(len(transactions)):
+                if transactions[i].no != i + 1:
+                    transactions[i].no = i + 1
+                    self.is_modified = True

src/accounting/transaction/query.py

@@ -0,0 +1,65 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/18
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The transaction query.
+
+"""
+from datetime import datetime
+
+import sqlalchemy as sa
+from flask import request
+
+from accounting.models import Transaction
+from accounting.utils.query import parse_query_keywords
+
+
+def get_transaction_query() -> list[Transaction]:
+    """Returns the transactions, optionally filtered by the query.
+
+    :return: The transactions.
+    """
+    keywords: list[str] = parse_query_keywords(request.args.get("q"))
+    if len(keywords) == 0:
+        return Transaction.query\
+            .order_by(Transaction.date, Transaction.no).all()
+    conditions: list[sa.BinaryExpression] = []
+    for k in keywords:
+        sub_conditions: list[sa.BinaryExpression] \
+            = [Transaction.note.contains(k)]
+        date: datetime
+        try:
+            date = datetime.strptime(k, "%Y")
+            sub_conditions.append(
+                sa.extract("year", Transaction.date) == date.year)
+        except ValueError:
+            pass
+        try:
+            date = datetime.strptime(k, "%Y/%m")
+            sub_conditions.append(sa.and_(
+                sa.extract("year", Transaction.date) == date.year,
+                sa.extract("month", Transaction.date) == date.month))
+        except ValueError:
+            pass
+        try:
+            date = datetime.strptime(f"2000/{k}", "%Y/%m/%d")
+            sub_conditions.append(sa.and_(
+                sa.extract("month", Transaction.date) == date.month,
+                sa.extract("day", Transaction.date) == date.day))
+        except ValueError:
+            pass
+        conditions.append(sa.or_(*sub_conditions))
+    return Transaction.query.filter(*conditions)\
+        .order_by(Transaction.date, Transaction.no).all()

src/accounting/transaction/template.py

@@ -0,0 +1,119 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/25
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The template filters and globals for the transaction management.
+
+"""
+from datetime import date, timedelta
+from decimal import Decimal
+from html import escape
+from urllib.parse import ParseResult, urlparse, parse_qsl, urlencode, \
+    urlunparse
+
+from flask import request, current_app
+from flask_babel import get_locale
+
+from accounting.locale import gettext
+from accounting.models import Currency
+
+
+def with_type(uri: str) -> str:
+    """Adds the transaction type to the URI, if it is specified.
+
+    :param uri: The URI.
+    :return: The result URL, optionally with the transaction type added.
+    """
+    if "as" not in request.args:
+        return uri
+    uri_p: ParseResult = urlparse(uri)
+    params: list[tuple[str, str]] = parse_qsl(uri_p.query)
+    params = [x for x in params if x[0] != "next"]
+    params.append(("as", request.args["as"]))
+    parts: list[str] = list(uri_p)
+    parts[4] = urlencode(params)
+    return urlunparse(parts)
+
+
+def format_amount(value: Decimal | None) -> str:
+    """Formats an amount for readability.
+
+    :param value: The amount.
+    :return: The formatted amount text.
+    """
+    if value is None or value == 0:
+        return "-"
+    whole: int = int(value)
+    frac: Decimal = (value - whole).normalize()
+    return "{:,}".format(whole) + str(frac)[1:]
+
+
+def format_date(value: date) -> str:
+    """Formats a date to be human-friendly.
+
+    :param value: The date.
+    :return: The human-friendly date text.
+    """
+    today: date = date.today()
+    if value == today:
+        return gettext("Today")
+    if value == today - timedelta(days=1):
+        return gettext("Yesterday")
+    if value == today + timedelta(days=1):
+        return gettext("Tomorrow")
+    locale = str(get_locale())
+    if locale == "zh" or locale.startswith("zh_"):
+        if value == today - timedelta(days=2):
+            return gettext("The day before yesterday")
+        if value == today + timedelta(days=2):
+            return gettext("The day after tomorrow")
+    if locale == "zh" or locale.startswith("zh_"):
+        weekdays = ["一", "二", "三", "四", "五", "六", "日"]
+        weekday = weekdays[value.weekday()]
+    else:
+        weekday = value.strftime("%a")
+    if value.year != today.year:
+        return "{}/{}/{}({})".format(
+            value.year, value.month, value.day, weekday)
+    return "{}/{}({})".format(value.month, value.day, weekday)
+
+
+def text2html(value: str) -> str:
+    """Converts plain text into HTML.
+
+    :param value: The plain text.
+    :return: The HTML.
+    """
+    s: str = escape(value)
+    s = s.replace("\n", "<br>")
+    s = s.replace("  ", " &nbsp;")
+    return s
+
+
+def currency_options() -> str:
+    """Returns the currency options.
+
+    :return: The currency options.
+    """
+    return Currency.query.order_by(Currency.code).all()
+
+
+def default_currency_code() -> str:
+    """Returns the default currency code.
+
+    :return: The default currency code.
+    """
+    with current_app.app_context():
+        return current_app.config.get("DEFAULT_CURRENCY", "USD")

src/accounting/transaction/views.py

@@ -0,0 +1,223 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/18
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The views for the transaction management.
+
+"""
+from datetime import date
+from urllib.parse import parse_qsl, urlencode
+
+import sqlalchemy as sa
+from flask import Blueprint, render_template, session, redirect, request, \
+    flash, url_for
+from werkzeug.datastructures import ImmutableMultiDict
+
+from accounting import db
+from accounting.locale import lazy_gettext
+from accounting.models import Transaction
+from accounting.utils.flash_errors import flash_form_errors
+from accounting.utils.next_uri import inherit_next, or_next
+from accounting.utils.pagination import Pagination
+from accounting.utils.permission import has_permission, can_view, can_edit
+from accounting.utils.user import get_current_user_pk
+from .dispatcher import TransactionType, get_txn_type, TXN_TYPE_OBJ
+from .template import with_type, format_amount, format_date, text2html, \
+    currency_options, default_currency_code
+from .forms import sort_transactions_in, TransactionReorderForm
+from .query import get_transaction_query
+
+bp: Blueprint = Blueprint("transaction", __name__)
+"""The view blueprint for the transaction management."""
+bp.add_app_template_filter(with_type, "accounting_txn_with_type")
+bp.add_app_template_filter(format_amount, "accounting_txn_format_amount")
+bp.add_app_template_filter(format_date, "accounting_txn_format_date")
+bp.add_app_template_filter(text2html, "accounting_txn_text2html")
+bp.add_app_template_global(currency_options, "accounting_txn_currency_options")
+bp.add_app_template_global(default_currency_code,
+                           "accounting_txn_default_currency_code")
+
+
+@bp.get("", endpoint="list")
+@has_permission(can_view)
+def list_transactions() -> str:
+    """Lists the transactions.
+
+    :return: The transaction list.
+    """
+    transactions: list[Transaction] = get_transaction_query()
+    pagination: Pagination = Pagination[Transaction](transactions)
+    return render_template("accounting/transaction/list.html",
+                           list=pagination.list, pagination=pagination,
+                           types=TXN_TYPE_OBJ)
+
+
+@bp.get("/create/<transactionType:txn_type>", endpoint="create")
+@has_permission(can_edit)
+def show_add_transaction_form(txn_type: TransactionType) -> str:
+    """Shows the form to add a transaction.
+
+    :param txn_type: The transaction type.
+    :return: The form to add a transaction.
+    """
+    form: txn_type.form
+    if "form" in session:
+        form = txn_type.form(ImmutableMultiDict(parse_qsl(session["form"])))
+        del session["form"]
+        form.validate()
+    else:
+        form = txn_type.form()
+    return txn_type.render_create_template(form)
+
+
+@bp.post("/store/<transactionType:txn_type>", endpoint="store")
+@has_permission(can_edit)
+def add_transaction(txn_type: TransactionType) -> redirect:
+    """Adds a transaction.
+
+    :param txn_type: The transaction type.
+    :return: The redirection to the transaction detail on success, or the
+        transaction creation form on error.
+    """
+    form: txn_type.form = txn_type.form(request.form)
+    if not form.validate():
+        flash_form_errors(form)
+        session["form"] = urlencode(list(request.form.items()))
+        return redirect(inherit_next(with_type(
+            url_for("accounting.transaction.create", txn_type=txn_type))))
+    txn: Transaction = Transaction()
+    form.populate_obj(txn)
+    db.session.add(txn)
+    db.session.commit()
+    flash(lazy_gettext("The transaction is added successfully"), "success")
+    return redirect(inherit_next(__get_detail_uri(txn)))
+
+
+@bp.get("/<transaction:txn>", endpoint="detail")
+@has_permission(can_view)
+def show_transaction_detail(txn: Transaction) -> str:
+    """Shows the transaction detail.
+
+    :param txn: The transaction.
+    :return: The detail.
+    """
+    txn_type: TransactionType = get_txn_type(txn)
+    return txn_type.render_detail_template(txn)
+
+
+@bp.get("/<transaction:txn>/edit", endpoint="edit")
+@has_permission(can_edit)
+def show_transaction_edit_form(txn: Transaction) -> str:
+    """Shows the form to edit a transaction.
+
+    :param txn: The transaction.
+    :return: The form to edit the transaction.
+    """
+    txn_type: TransactionType = get_txn_type(txn)
+    form: txn_type.form
+    if "form" in session:
+        form = txn_type.form(ImmutableMultiDict(parse_qsl(session["form"])))
+        del session["form"]
+        form.validate()
+    else:
+        form = txn_type.form(obj=txn)
+    return txn_type.render_edit_template(txn, form)
+
+
+@bp.post("/<transaction:txn>/update", endpoint="update")
+@has_permission(can_edit)
+def update_transaction(txn: Transaction) -> redirect:
+    """Updates a transaction.
+
+    :param txn: The transaction.
+    :return: The redirection to the transaction detail on success, or the
+        transaction edit form on error.
+    """
+    txn_type: TransactionType = get_txn_type(txn)
+    form: txn_type.form = txn_type.form(request.form)
+    if not form.validate():
+        flash_form_errors(form)
+        session["form"] = urlencode(list(request.form.items()))
+        return redirect(inherit_next(with_type(
+            url_for("accounting.transaction.edit", txn=txn))))
+    with db.session.no_autoflush:
+        form.populate_obj(txn)
+    if not form.is_modified:
+        flash(lazy_gettext("The transaction was not modified."), "success")
+        return redirect(inherit_next(with_type(__get_detail_uri(txn))))
+    txn.updated_by_id = get_current_user_pk()
+    txn.updated_at = sa.func.now()
+    db.session.commit()
+    flash(lazy_gettext("The transaction is updated successfully."), "success")
+    return redirect(inherit_next(with_type(__get_detail_uri(txn))))
+
+
+@bp.post("/<transaction:txn>/delete", endpoint="delete")
+@has_permission(can_edit)
+def delete_transaction(txn: Transaction) -> redirect:
+    """Deletes a transaction.
+
+    :param txn: The transaction.
+    :return: The redirection to the transaction list on success, or the
+        transaction detail on error.
+    """
+    txn.delete()
+    sort_transactions_in(txn.date, txn.id)
+    db.session.commit()
+    flash(lazy_gettext("The transaction is deleted successfully."), "success")
+    return redirect(or_next(with_type(url_for("accounting.transaction.list"))))
+
+
+@bp.get("/dates/<date:txn_date>", endpoint="order")
+@has_permission(can_view)
+def show_transaction_order(txn_date: date) -> str:
+    """Shows the order of the transactions in a same date.
+
+    :param txn_date: The date.
+    :return: The order of the transactions in the date.
+    """
+    transactions: list[Transaction] = Transaction.query\
+        .filter(Transaction.date == txn_date)\
+        .order_by(Transaction.no).all()
+    return render_template("accounting/transaction/order.html",
+                           date=txn_date, list=transactions)
+
+
+@bp.post("/dates/<date:txn_date>", endpoint="sort")
+@has_permission(can_edit)
+def sort_accounts(txn_date: date) -> redirect:
+    """Reorders the transactions in a date.
+
+    :param txn_date: The date.
+    :return: The redirection to the incoming account or the account list.  The
+        reordering operation does not fail.
+    """
+    form: TransactionReorderForm = TransactionReorderForm(txn_date)
+    form.save_order()
+    if not form.is_modified:
+        flash(lazy_gettext("The order was not modified."), "success")
+        return redirect(or_next(url_for("accounting.account.list")))
+    db.session.commit()
+    flash(lazy_gettext("The order is updated successfully."), "success")
+    return redirect(or_next(url_for("accounting.account.list")))
+
+
+def __get_detail_uri(txn: Transaction) -> str:
+    """Returns the detail URI of a transaction.
+
+    :param txn: The transaction.
+    :return: The detail URI of the transaction.
+    """
+    return url_for("accounting.transaction.detail", txn=txn)

src/accounting/utils/pagination.py

@@ -115,7 +115,7 @@ class EmptyPagination(AbstractPagination[T]):
 
 class NonEmptyPagination(AbstractPagination[T]):
     """The pagination with real data."""
-    PAGE_SIZE_OPTIONS: list[int] = [10, 100, 200]
+    PAGE_SIZE_OPTION_VALUES: list[int] = [10, 100, 200]
     """The page size options."""
 
     def __init__(self, items: list[T], is_reversed: bool = False):
@@ -278,7 +278,7 @@ class NonEmptyPagination(AbstractPagination[T]):
             return []
         return [Link(str(x), self.__uri_size(x),
                      is_current=x == self.page_size)
-                for x in self.PAGE_SIZE_OPTIONS]
+                for x in self.PAGE_SIZE_OPTION_VALUES]
 
     def __uri_size(self, page_size: int) -> str:
         """Returns the URI of a page size.

src/accounting/utils/strip_text.py

@@ -19,6 +19,7 @@
 This module should not import any other module from the application.
 
 """
+import re
 
 
 def strip_text(s: str | None) -> str | None:
@@ -31,3 +32,15 @@ def strip_text(s: str | None) -> str | None:
         return None
     s = s.strip()
     return s if s != "" else None
+
+
+def strip_multiline_text(s: str | None) -> str | None:
+    """The filter to strip a piece of multi-line text.
+
+    :param s: The text input string.
+    :return: The filtered string.
+    """
+    if s is None:
+        return None
+    s = re.sub(r"^\s*\n", "", s.rstrip())
+    return s if s != "" else None

tests/testlib_txn.py

@@ -0,0 +1,443 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/27
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The common test libraries for the transaction test cases.
+
+"""
+import re
+from decimal import Decimal
+from datetime import date
+from secrets import randbelow
+
+from flask import Flask
+
+from test_site import db
+
+NEXT_URI: str = "/_next"
+"""The next URI."""
+NON_EMPTY_NOTE: str = "  This is \n\na test."
+"""The stripped content of an non-empty note."""
+EMPTY_NOTE: str = " \n\n  "
+"""The empty note content."""
+
+
+class Accounts:
+    """The shortcuts to the common accounts."""
+    CASH: str = "1111-001"
+    BANK: str = "1113-001"
+    SALES: str = "4111-001"
+    SERVICE: str = "4611-001"
+    AGENCY: str = "4711-001"
+    OFFICE: str = "5153-001"
+    TRAVEL: str = "5154-001"
+    INTEREST: str = "4111-001"
+    DONATION: str = "7481-001"
+    RENT: str = "7482-001"
+
+
+def get_add_form(csrf_token: str) -> dict[str, str]:
+    """Returns the form data to add a new transaction.
+
+    :param csrf_token: The CSRF token.
+    :return: The form data to add a new transaction.
+    """
+    return {"csrf_token": csrf_token,
+            "next": NEXT_URI,
+            "date": date.today().isoformat(),
+            "currency-0-code": "USD",
+            "currency-0-debit-0-no": "16",
+            "currency-0-debit-0-account_code": Accounts.CASH,
+            "currency-0-debit-0-summary": " ",
+            "currency-0-debit-0-amount": " 495.26 ",
+            "currency-0-debit-6-no": "2",
+            "currency-0-debit-6-account_code": Accounts.BANK,
+            "currency-0-debit-6-summary": " Deposit ",
+            "currency-0-debit-6-amount": "6000",
+            "currency-0-debit-12-no": "2",
+            "currency-0-debit-12-account_code": Accounts.OFFICE,
+            "currency-0-debit-12-summary": " Pens ",
+            "currency-0-debit-12-amount": "4.99",
+            "currency-0-credit-2-no": "6",
+            "currency-0-credit-2-account_code": Accounts.SERVICE,
+            "currency-0-credit-2-summary": " ",
+            "currency-0-credit-2-amount": "5500",
+            "currency-0-credit-7-account_code": Accounts.SALES,
+            "currency-0-credit-7-summary": " ",
+            "currency-0-credit-7-amount": "950",
+            "currency-0-credit-27-account_code": Accounts.INTEREST,
+            "currency-0-credit-27-summary": " ",
+            "currency-0-credit-27-amount": "50.25",
+            "currency-3-no": "2",
+            "currency-3-code": "JPY",
+            "currency-3-debit-2-no": "2",
+            "currency-3-debit-2-account_code": Accounts.CASH,
+            "currency-3-debit-2-summary": " ",
+            "currency-3-debit-2-amount": "15000",
+            "currency-3-debit-9-no": "5",
+            "currency-3-debit-9-account_code": Accounts.BANK,
+            "currency-3-debit-9-summary": " Deposit ",
+            "currency-3-debit-9-amount": "95000",
+            "currency-3-credit-3-account_code": Accounts.AGENCY,
+            "currency-3-credit-3-summary": " Realtor ",
+            "currency-3-credit-3-amount": "65000",
+            "currency-3-credit-5-no": "4",
+            "currency-3-credit-5-account_code": Accounts.DONATION,
+            "currency-3-credit-5-summary": " Donation ",
+            "currency-3-credit-5-amount": "45000",
+            "currency-16-code": "TWD",
+            "currency-16-debit-2-no": "2",
+            "currency-16-debit-2-account_code": Accounts.CASH,
+            "currency-16-debit-2-summary": " ",
+            "currency-16-debit-2-amount": "10000",
+            "currency-16-debit-9-no": "2",
+            "currency-16-debit-9-account_code": Accounts.TRAVEL,
+            "currency-16-debit-9-summary": " Gas ",
+            "currency-16-debit-9-amount": "30000",
+            "currency-16-credit-6-no": "6",
+            "currency-16-credit-6-account_code": Accounts.RENT,
+            "currency-16-credit-6-summary": " Rent ",
+            "currency-16-credit-6-amount": "35000",
+            "currency-16-credit-9-account_code": Accounts.DONATION,
+            "currency-16-credit-9-summary": " Donation ",
+            "currency-16-credit-9-amount": "5000",
+            "note": f"\n \n\n  \n{NON_EMPTY_NOTE}  \n  \n\n  "}
+
+
+def get_unchanged_update_form(txn_id: int, app: Flask, csrf_token: str) \
+        -> dict[str, str]:
+    """Returns the form data to update a transaction, where the data are not
+    changed.
+
+    :param txn_id: The transaction ID.
+    :param app: The Flask application.
+    :param csrf_token: The CSRF token.
+    :return: The form data to update the transaction, where the data are not
+        changed.
+    """
+    from accounting.models import Transaction, TransactionCurrency
+    with app.app_context():
+        txn: Transaction | None = db.session.get(Transaction, txn_id)
+        assert txn is not None
+        currencies: list[TransactionCurrency] = txn.currencies
+
+    form: dict[str, str] = {"csrf_token": csrf_token,
+                            "next": NEXT_URI,
+                            "date": txn.date,
+                            "note": "  \n \n\n  " if txn.note is None
+                            else f"\n    \n\n \n  \n{txn.note}  \n\n   "}
+    currency_indices_used: set[int] = set()
+    currency_no: int = 0
+    for currency in currencies:
+        currency_index: int = __get_new_index(currency_indices_used)
+        currency_no = currency_no + 3 + randbelow(3)
+        currency_prefix: str = f"currency-{currency_index}"
+        form[f"{currency_prefix}-no"] = str(currency_no)
+        form[f"{currency_prefix}-code"] = currency.code
+        entry_indices_used: set[int]
+        entry_no: int
+        prefix: str
+
+        entry_indices_used = set()
+        entry_no = 0
+        for entry in currency.debit:
+            entry_index: int = __get_new_index(entry_indices_used)
+            entry_no = entry_no + 3 + randbelow(3)
+            prefix = f"{currency_prefix}-debit-{entry_index}"
+            form[f"{prefix}-eid"] = str(entry.id)
+            form[f"{prefix}-no"] = str(entry_no)
+            form[f"{prefix}-account_code"] = entry.account.code
+            form[f"{prefix}-summary"] \
+                = "  " if entry.summary is None else f" {entry.summary} "
+            form[f"{prefix}-amount"] = str(entry.amount)
+
+        entry_indices_used = set()
+        entry_no = 0
+        for entry in currency.credit:
+            entry_index: int = __get_new_index(entry_indices_used)
+            entry_no = entry_no + 3 + randbelow(3)
+            prefix = f"{currency_prefix}-credit-{entry_index}"
+            form[f"{prefix}-eid"] = str(entry.id)
+            form[f"{prefix}-no"] = str(entry_no)
+            form[f"{prefix}-account_code"] = entry.account.code
+            form[f"{prefix}-summary"] \
+                = "  " if entry.summary is None else f" {entry.summary} "
+            form[f"{prefix}-amount"] = str(entry.amount)
+
+    return form
+
+
+def __get_new_index(indices_used: set[int]) -> int:
+    """Returns a new random index that is not used.
+
+    :param indices_used: The set of indices that are already used.
+    :return: The newly-generated random index that is not used.
+    """
+    while True:
+        index: int = randbelow(100)
+        if index not in indices_used:
+            indices_used.add(index)
+            return index
+
+
+def get_update_form(txn_id: int, app: Flask,
+                    csrf_token: str, is_debit: bool | None) -> dict[str, str]:
+    """Returns the form data to update a transaction, where the data are
+    changed.
+
+    :param txn_id: The transaction ID.
+    :param app: The Flask application.
+    :param csrf_token: The CSRF token.
+    :param is_debit: True for a cash expense transaction, False for a cash
+        income transaction, or None for a transfer transaction
+    :return: The form data to update the transaction, where the data are
+        changed.
+    """
+    form: dict[str, str] = get_unchanged_update_form(
+        txn_id, app, csrf_token)
+
+    # Mess up the entries in a currency
+    currency_prefix: str = __get_currency_prefix(form, "USD")
+    if is_debit is None or is_debit:
+        form = __mess_up_debit(form, currency_prefix)
+    if is_debit is None or not is_debit:
+        form = __mess_up_credit(form, currency_prefix)
+
+    # Mess-up the currencies
+    form = __mess_up_currencies(form)
+
+    return form
+
+
+def __mess_up_debit(form: dict[str, str], currency_prefix: str) \
+        -> dict[str, str]:
+    """Mess up the debit journal entries in the form data.
+
+    :param form: The form data.
+    :param currency_prefix: The key prefix of the currency sub-form.
+    :return: The messed-up form.
+    """
+    key: str
+    m: re.Match
+
+    # Remove the office expense
+    key = [x for x in form
+           if x.startswith(currency_prefix)
+           and form[x] == Accounts.OFFICE][0]
+    m = re.match(r"^((.+-)\d+-)account_code$", key)
+    debit_prefix: str = m.group(2)
+    entry_prefix: str = m.group(1)
+    amount: Decimal = Decimal(form[f"{entry_prefix}amount"])
+    form = {x: form[x] for x in form if not x.startswith(entry_prefix)}
+    # Add a new travel expense
+    indices: set[int] = set()
+    for key in form:
+        m = re.match(r"^.+-(\d+)-amount$", key)
+        if m is not None:
+            indices.add(int(m.group(1)))
+    new_index: int = max(indices) + 5 + randbelow(20)
+    min_no: int = min({int(form[x]) for x in form if x.endswith("-no")
+                       and x.startswith(debit_prefix)})
+    form[f"{debit_prefix}{new_index}-no"] = str(1 + randbelow(min_no - 1))
+    form[f"{debit_prefix}{new_index}-amount"] = str(amount)
+    form[f"{debit_prefix}{new_index}-account_code"] = Accounts.TRAVEL
+    # Swap the cash and the bank order
+    key_cash: str = __get_entry_no_key(form, currency_prefix, Accounts.CASH)
+    key_bank: str = __get_entry_no_key(form, currency_prefix, Accounts.BANK)
+    form[key_cash], form[key_bank] = form[key_bank], form[key_cash]
+    return form
+
+
+def __mess_up_credit(form: dict[str, str], currency_prefix: str) \
+        -> dict[str, str]:
+    """Mess up the credit journal entries in the form data.
+
+    :param form: The form data.
+    :param currency_prefix: The key prefix of the currency sub-form.
+    :return: The messed-up form.
+    """
+    key: str
+    m: re.Match
+
+    # Remove the sales income
+    key = [x for x in form
+           if x.startswith(currency_prefix)
+           and form[x] == Accounts.SALES][0]
+    m = re.match(r"^((.+-)\d+-)account_code$", key)
+    credit_prefix: str = m.group(2)
+    entry_prefix: str = m.group(1)
+    amount: Decimal = Decimal(form[f"{entry_prefix}amount"])
+    form = {x: form[x] for x in form if not x.startswith(entry_prefix)}
+    # Add a new agency income
+    indices: set[int] = set()
+    for key in form:
+        m = re.match(r"^.+-(\d+)-amount$", key)
+        if m is not None:
+            indices.add(int(m.group(1)))
+    new_index: int = max(indices) + 5 + randbelow(20)
+    min_no: int = min({int(form[x]) for x in form if x.endswith("-no")
+                       and x.startswith(credit_prefix)})
+    form[f"{credit_prefix}{new_index}-no"] = str(1 + randbelow(min_no - 1))
+    form[f"{credit_prefix}{new_index}-amount"] = str(amount)
+    form[f"{credit_prefix}{new_index}-account_code"] = Accounts.AGENCY
+    # Swap the service and the interest order
+    key_srv: str = __get_entry_no_key(form, currency_prefix, Accounts.SERVICE)
+    key_int: str = __get_entry_no_key(form, currency_prefix, Accounts.INTEREST)
+    form[key_srv], form[key_int] = form[key_int], form[key_srv]
+    return form
+
+
+def __mess_up_currencies(form: dict[str, str]) -> dict[str, str]:
+    """Mess up the currency sub-forms in the form data.
+
+    :param form: The form data.
+    :return: The messed-up form.
+    """
+    key: str
+    m: re.Match
+
+    # Remove JPY
+    currency_prefix: str = __get_currency_prefix(form, "JPY")
+    form = {x: form[x] for x in form if not x.startswith(currency_prefix)}
+    # Add AUD
+    indices: set[int] = set()
+    for key in form:
+        m = re.match(r"^currency-(\d+)-code$", key)
+        if m is not None:
+            indices.add(int(m.group(1)))
+    new_index: int = max(indices) + 5 + randbelow(20)
+    min_no: int = min({int(form[x]) for x in form if x.endswith("-no")
+                       and "-debit-" not in x and "-credit-" not in x})
+    prefix: str = f"currency-{new_index}-"
+    form.update({
+        f"{prefix}code": "AUD",
+        f"{prefix}no": str(1 + randbelow(min_no - 1)),
+        f"{prefix}debit-0-no": "6",
+        f"{prefix}debit-0-account_code": Accounts.OFFICE,
+        f"{prefix}debit-0-summary": " Envelop ",
+        f"{prefix}debit-0-amount": "5.45",
+        f"{prefix}debit-14-no": "6",
+        f"{prefix}debit-14-account_code": Accounts.CASH,
+        f"{prefix}debit-14-summary": "  ",
+        f"{prefix}debit-14-amount": "14.55",
+        f"{prefix}credit-16-no": "7",
+        f"{prefix}credit-16-account_code": Accounts.RENT,
+        f"{prefix}credit-16-summary": " Bike ",
+        f"{prefix}credit-16-amount": "19.5",
+        f"{prefix}credit-22-no": "5",
+        f"{prefix}credit-22-account_code": Accounts.DONATION,
+        f"{prefix}credit-22-summary": " Artist ",
+        f"{prefix}credit-22-amount": "0.5",
+    })
+    # Swap the USD and TWD order
+    usd_prefix: str = __get_currency_prefix(form, "USD")
+    key_usd: str = f"{usd_prefix}no"
+    twd_prefix: str = __get_currency_prefix(form, "TWD")
+    key_twd: str = f"{twd_prefix}no"
+    form[key_usd], form[key_twd] = form[key_twd], form[key_usd]
+    # Change TWD to EUR
+    key = [x for x in form if form[x] == "TWD"][0]
+    form[key] = "EUR"
+    return form
+
+
+def __get_entry_no_key(form: dict[str, str], currency_prefix: str,
+                       code: str) -> str:
+    """Returns the key of an entry number in the form data.
+
+    :param form: The form data.
+    :param currency_prefix: The prefix of the currency.
+    :param code: The code of the account.
+    :return: The key of the entry number in the form data.
+    """
+    key: str = [x for x in form
+                if x.startswith(currency_prefix)
+                and form[x] == code][0]
+    m: re.Match = re.match(r"^(.+-\d+-)account_code$", key)
+    return f"{m.group(1)}no"
+
+
+def __get_currency_prefix(form: dict[str, str], code: str) -> str:
+    """Returns the prefix of a currency in the form data.
+
+    :param form: The form data.
+    :param code: The code of the currency.
+    :return: The prefix of the currency.
+    """
+    key: str = [x for x in form if form[x] == code][0]
+    m: re.Match = re.match(r"^(.+-)code$", key)
+    return m.group(1)
+
+
+def match_txn_detail(location: str) -> int:
+    """Validates if the redirect location is the transaction detail, and
+    returns the transaction ID on success.
+
+    :param location: The redirect location.
+    :return: The transaction ID.
+    :raise AssertionError: When the location is not the transaction detail.
+    """
+    m: re.Match = re.match(
+        r"^/accounting/transactions/(\d+)\?next=%2F_next",
+        location)
+    assert m is not None
+    return int(m.group(1))
+
+
+def set_negative_amount(form: dict[str, str]) -> None:
+    """Sets a negative amount in the form data, keeping the balance.
+
+    :param form: The form data.
+    :return: None.
+    """
+    amount_keys: list[str] = []
+    prefix: str = ""
+    for key in form.keys():
+        m: re.Match = re.match(r"^(.+)-\d+-amount$", key)
+        if m is None:
+            continue
+        if prefix != "" and prefix != m.group(1):
+            continue
+        prefix = m.group(1)
+        amount_keys.append(key)
+    form[amount_keys[0]] = str(-Decimal(form[amount_keys[0]]))
+    form[amount_keys[1]] = str(Decimal(form[amount_keys[1]])
+                               + 2 * Decimal(form[amount_keys[0]]))
+
+
+def remove_debit_in_a_currency(form: dict[str, str]) -> None:
+    """Removes credit entries in a currency sub-form.
+
+    :param form: The form data.
+    :return: None.
+    """
+    key: str = [x for x in form if "-debit-" in x][0]
+    m: re.Match = re.match(r"^(.+-debit-)", key)
+    keys: set[str] = {x for x in form if x.startswith(m.group(1))}
+    for key in keys:
+        del form[key]
+
+
+def remove_credit_in_a_currency(form: dict[str, str]) -> None:
+    """Removes credit entries in a currency sub-form.
+
+    :param form: The form data.
+    :return: None.
+    """
+    key: str = [x for x in form if "-credit-" in x][0]
+    m: re.Match = re.match(r"^(.+-credit-)", key)
+    keys: set[str] = {x for x in form if x.startswith(m.group(1))}
+    for key in keys:
+        del form[key]