Added the _get_currency_options method to the BasePageParams class, and applied it to the currency_options pseudo property of the PageParams classes of the ledger, income and expenses log, trial balance, income statement, and balance sheet reports.

src/accounting/report/reports/balance_sheet.py

@@ -362,12 +362,7 @@ class PageParams(BasePageParams):
             return url_for("accounting.report.balance-sheet",
                            currency=currency, period=self.period)
 
-        in_use: set[str] = set(db.session.scalars(
+        return self._get_currency_options(get_url, self.currency)
-            sa.select(JournalEntry.currency_code)
-            .group_by(JournalEntry.currency_code)).all())
-        return [OptionLink(str(x), get_url(x), x.code == self.currency.code)
-                for x in Currency.query.filter(Currency.code.in_(in_use))
-                .order_by(Currency.code).all()]
 
 
 class BalanceSheet(BaseReport):

src/accounting/report/reports/income_expenses.py

@@ -325,12 +325,7 @@ class PageParams(BasePageParams):
                            currency=currency, account=self.account,
                            period=self.period)
 
-        in_use: set[str] = set(db.session.scalars(
+        return self._get_currency_options(get_url, self.currency)
-            sa.select(JournalEntry.currency_code)
-            .group_by(JournalEntry.currency_code)).all())
-        return [OptionLink(str(x), get_url(x), x.code == self.currency.code)
-                for x in Currency.query.filter(Currency.code.in_(in_use))
-                .order_by(Currency.code).all()]
 
     @property
     def account_options(self) -> list[OptionLink]:

src/accounting/report/reports/income_statement.py

@@ -193,12 +193,7 @@ class PageParams(BasePageParams):
             return url_for("accounting.report.income-statement",
                            currency=currency, period=self.period)
 
-        in_use: set[str] = set(db.session.scalars(
+        return self._get_currency_options(get_url, self.currency)
-            sa.select(JournalEntry.currency_code)
-            .group_by(JournalEntry.currency_code)).all())
-        return [OptionLink(str(x), get_url(x), x.code == self.currency.code)
-                for x in Currency.query.filter(Currency.code.in_(in_use))
-                .order_by(Currency.code).all()]
 
 
 class IncomeStatement(BaseReport):

src/accounting/report/reports/ledger.py

@@ -297,12 +297,7 @@ class PageParams(BasePageParams):
                            currency=currency, account=self.account,
                            period=self.period)
 
-        in_use: set[str] = set(db.session.scalars(
+        return self._get_currency_options(get_url, self.currency)
-            sa.select(JournalEntry.currency_code)
-            .group_by(JournalEntry.currency_code)).all())
-        return [OptionLink(str(x), get_url(x), x.code == self.currency.code)
-                for x in Currency.query.filter(Currency.code.in_(in_use))
-                .order_by(Currency.code).all()]
 
     @property
     def account_options(self) -> list[OptionLink]:

src/accounting/report/reports/trial_balance.py

@@ -155,12 +155,7 @@ class PageParams(BasePageParams):
             return url_for("accounting.report.trial-balance",
                            currency=currency, period=self.period)
 
-        in_use: set[str] = set(db.session.scalars(
+        return self._get_currency_options(get_url, self.currency)
-            sa.select(JournalEntry.currency_code)
-            .group_by(JournalEntry.currency_code)).all())
-        return [OptionLink(str(x), get_url(x), x.code == self.currency.code)
-                for x in Currency.query.filter(Currency.code.in_(in_use))
-                .order_by(Currency.code).all()]
 
 
 class TrialBalance(BaseReport):

src/accounting/report/reports/utils/base_page_params.py

@@ -22,9 +22,13 @@ from abc import ABC, abstractmethod
 from urllib.parse import urlparse, ParseResult, parse_qsl, urlencode, \
     urlunparse
 
+import sqlalchemy as sa
 from flask import request
 
+from accounting import db
+from accounting.models import Currency, JournalEntry
 from accounting.utils.txn_types import TransactionType
+from .option_link import OptionLink
 from .report_chooser import ReportChooser
 
 
@@ -66,3 +70,19 @@ class BasePageParams(ABC):
         parts: list[str] = list(uri_p)
         parts[4] = urlencode(params)
         return urlunparse(parts)
+
+    @staticmethod
+    def _get_currency_options(get_url: t.Callable[[Currency], str],
+                              active_currency: Currency) -> list[OptionLink]:
+        """Returns the currency options.
+
+        :param get_url: The callback to return the URL of a currency.
+        :param active_currency: The active currency.
+        :return: The currency options.
+        """
+        in_use: set[str] = set(db.session.scalars(
+            sa.select(JournalEntry.currency_code)
+            .group_by(JournalEntry.currency_code)).all())
+        return [OptionLink(str(x), get_url(x), x.code == active_currency.code)
+                for x in Currency.query.filter(Currency.code.in_(in_use))
+                .order_by(Currency.code).all()]