From 241ad337c8ac7782ab2818fa8ead5883966f8cb0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BE=9D=E7=91=AA=E8=B2=93?= <imacat@mail.imacat.idv.tw>
Date: Wed, 1 Feb 2023 16:30:02 +0800
Subject: [PATCH] Added the "accounting.utils.next_uri" utilities to fixed how
 the next URI works.

---
 src/accounting/__init__.py                    |  5 ++
 src/accounting/account/views.py               | 17 +++--
 .../templates/accounting/account/detail.html  |  9 ++-
 .../templates/accounting/account/edit.html    |  2 +-
 .../templates/accounting/account/list.html    |  6 +-
 src/accounting/utils/next_url.py              | 75 +++++++++++++++++++
 6 files changed, 101 insertions(+), 13 deletions(-)
 create mode 100644 src/accounting/utils/next_url.py

diff --git a/src/accounting/__init__.py b/src/accounting/__init__.py
index edca8b5..4c0cc09 100644
--- a/src/accounting/__init__.py
+++ b/src/accounting/__init__.py
@@ -106,4 +106,9 @@ def init_app(app: Flask, user_utils: AbstractUserUtils,
     from . import account
     account.init_app(app, bp)
 
+    from .utils.next_url import append_next, inherit_next, or_next
+    bp.add_app_template_filter(append_next, "append_next")
+    bp.add_app_template_filter(inherit_next, "inherit_next")
+    bp.add_app_template_filter(or_next, "or_next")
+
     app.register_blueprint(bp)
diff --git a/src/accounting/account/views.py b/src/accounting/account/views.py
index e4215db..aa4f0d9 100644
--- a/src/accounting/account/views.py
+++ b/src/accounting/account/views.py
@@ -26,6 +26,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting.database import db
 from accounting.locale import lazy_gettext
 from accounting.models import Account, BaseAccount
+from accounting.utils.next_url import inherit_next, or_next
 from accounting.utils.pagination import Pagination
 from accounting.utils.permission import can_view, has_permission, can_edit
 from .forms import AccountForm, sort_accounts_in
@@ -79,13 +80,14 @@ def add_account() -> redirect:
             for error in form.errors[key]:
                 flash(error, "error")
         session["form"] = urlencode(list(request.form.items()))
-        return redirect(url_for("accounting.account.create"))
+        return redirect(inherit_next(url_for("accounting.account.create")))
     account: Account = Account()
     form.populate_obj(account)
     db.session.add(account)
     db.session.commit()
     flash(lazy_gettext("The account is added successfully"), "success")
-    return redirect(url_for("accounting.account.detail", account=account))
+    return redirect(inherit_next(url_for("accounting.account.detail",
+                                         account=account)))
 
 
 @bp.get("/<account:account>", endpoint="detail")
@@ -130,16 +132,19 @@ def update_account(account: Account) -> redirect:
             for error in form.errors[key]:
                 flash(error, "error")
         session["form"] = urlencode(list(request.form.items()))
-        return redirect(url_for("accounting.account.edit", account=account))
+        return redirect(inherit_next(url_for("accounting.account.edit",
+                                             account=account)))
     with db.session.no_autoflush:
         form.populate_obj(account)
     if not db.session.is_modified(account):
         flash(lazy_gettext("The account was not modified."), "success")
-        return redirect(url_for("accounting.account.detail", account=account))
+        return redirect(inherit_next(url_for("accounting.account.detail",
+                                             account=account)))
     form.post_update(account)
     db.session.commit()
     flash(lazy_gettext("The account is updated successfully."), "success")
-    return redirect(url_for("accounting.account.detail", account=account))
+    return redirect(inherit_next(url_for("accounting.account.detail",
+                                         account=account)))
 
 
 @bp.post("/<account:account>/delete", endpoint="delete")
@@ -156,4 +161,4 @@ def delete_account(account: Account) -> redirect:
     sort_accounts_in(account.base_code, account.id)
     db.session.commit()
     flash(lazy_gettext("The account is deleted successfully."), "success")
-    return redirect(url_for("accounting.account.list"))
+    return redirect(or_next(url_for("accounting.account.list")))
diff --git a/src/accounting/templates/accounting/account/detail.html b/src/accounting/templates/accounting/account/detail.html
index 4e8aa4f..49a90f5 100644
--- a/src/accounting/templates/accounting/account/detail.html
+++ b/src/accounting/templates/accounting/account/detail.html
@@ -26,12 +26,12 @@ First written: 2023/1/31
 {% block content %}
 
 <div class="btn-group mb-3">
-  <a class="btn btn-primary" href="{{ request.args.get("next") or url_for("accounting.account.list") }}">
+  <a class="btn btn-primary" href="{{ url_for("accounting.account.list")|or_next }}">
     <i class="fa-solid fa-circle-chevron-left"></i>
     {{ A_("Back") }}
   </a>
   {% if can_edit_accounting() %}
-    <a class="btn btn-primary d-none d-md-inline" href="{{ url_for("accounting.account.edit", account=obj) + ("?next=" + request.args["next"] if "next" in request.args else "") }}">
+    <a class="btn btn-primary d-none d-md-inline" href="{{ url_for("accounting.account.edit", account=obj)|inherit_next }}">
       <i class="fa-solid fa-gear"></i>
       {{ A_("Settings") }}
     </a>
@@ -44,7 +44,7 @@ First written: 2023/1/31
 
 {% if can_edit_accounting() %}
   <div class="d-md-none material-fab">
-    <a class="btn btn-primary" href="{{ url_for("accounting.account.edit", account=obj) + ("?next=" + request.args["next"] if "next" in request.args else "") }}">
+    <a class="btn btn-primary" href="{{ url_for("accounting.account.edit", account=obj)|inherit_next }}">
       <i class="fa-solid fa-pen-to-square"></i>
     </a>
   </div>
@@ -53,6 +53,9 @@ First written: 2023/1/31
 {% if can_edit_accounting() %}
   <form id="delete-form" action="{{ url_for("accounting.account.delete", account=obj) }}" method="post">
     <input id="csrf_token" 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="delete-modal" tabindex="-1" aria-labelledby="delete-model-label" aria-hidden="true">
       <div class="modal-dialog">
         <div class="modal-content">
diff --git a/src/accounting/templates/accounting/account/edit.html b/src/accounting/templates/accounting/account/edit.html
index 098207b..15514b2 100644
--- a/src/accounting/templates/accounting/account/edit.html
+++ b/src/accounting/templates/accounting/account/edit.html
@@ -23,6 +23,6 @@ First written: 2023/2/1
 
 {% block header %}{% block title %}{{ A_("%(account)s Settings", account=account) }}{% endblock %}{% endblock %}
 
-{% block back_url %}{{ url_for("accounting.account.detail", account=account) + ("?next=" + request.args["next"] if "next" in request.args else "") }}{% endblock %}
+{% block back_url %}{{ url_for("accounting.account.detail", account=account)|inherit_next }}{% endblock %}
 
 {% block action_url %}{{ url_for("accounting.account.update", account=account) }}{% endblock %}
diff --git a/src/accounting/templates/accounting/account/list.html b/src/accounting/templates/accounting/account/list.html
index 79f57f2..f2dc150 100644
--- a/src/accounting/templates/accounting/account/list.html
+++ b/src/accounting/templates/accounting/account/list.html
@@ -27,14 +27,14 @@ First written: 2023/1/30
 
 {% if can_edit_accounting() %}
   <div class="btn-group mb-3 d-none d-md-block">
-    <a class="btn btn-primary" href="{{ url_for("accounting.account.create") }}">
+    <a class="btn btn-primary" href="{{ url_for("accounting.account.create")|append_next }}">
       <i class="fa-solid fa-user-plus"></i>
       {{ A_("New") }}
     </a>
   </div>
 
   <div class="d-md-none material-fab">
-    <a class="btn btn-primary" href="{{ url_for("accounting.account.create") }}">
+    <a class="btn btn-primary" href="{{ url_for("accounting.account.create")|append_next }}">
       <i class="fa-solid fa-plus"></i>
     </a>
   </div>
@@ -61,7 +61,7 @@ First written: 2023/1/30
 
   <div class="list-group">
   {% for item in list %}
-    <a class="list-group-item list-group-item-action" href="{{ url_for("accounting.account.detail", account=item) }}">
+    <a class="list-group-item list-group-item-action" href="{{ url_for("accounting.account.detail", account=item)|append_next }}">
       {{ item }}
     </a>
   {% endfor %}
diff --git a/src/accounting/utils/next_url.py b/src/accounting/utils/next_url.py
new file mode 100644
index 0000000..4f10112
--- /dev/null
+++ b/src/accounting/utils/next_url.py
@@ -0,0 +1,75 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/1
+
+#  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 utilities to handle the next URL.
+
+This module should not import any other module from the application.
+
+"""
+from urllib.parse import urlparse, parse_qsl, ParseResult, urlencode, \
+    urlunparse
+
+from flask import request
+
+
+def append_next(uri: str) -> str:
+    """Appends the current URI as the next URI to the query argument.
+
+    :param uri: The URI.
+    :return: The URI with the current URI appended as the next URI.
+    """
+    next_uri: str = request.full_path if request.query_string else request.path
+    return __set_next(uri, next_uri)
+
+
+def inherit_next(uri: str) -> str:
+    """Inherits the current next URI to the query argument, if exists.
+
+    :param uri: The URI.
+    :return: The URI with the current next URI added at the query argument.
+    """
+    next_uri: str | None = request.form.get("next") \
+        if request.method == "POST" else request.args.get("next")
+    if next_uri is None:
+        return uri
+    return __set_next(uri, next_uri)
+
+
+def or_next(uri: str) -> str:
+    """Returns the next URI, if exists, or the supplied URI.
+
+    :param uri: The URI.
+    :return: The next URI or the supplied URI.
+    """
+    next_uri: str | None = request.form.get("next") \
+        if request.method == "POST" else request.args.get("next")
+    return uri if next_uri is None else next_uri
+
+
+def __set_next(uri: str, next_uri: str) -> str:
+    """Sets the next URI to the query arguments.
+
+    :param uri: The URI.
+    :param next_uri: The next URI.
+    :return: The URI with the next URI set.
+    """
+    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(("next", next_uri))
+    parts: list[str] = list(uri_p)
+    parts[4] = urlencode(params)
+    return urlunparse(parts)