Added the flash_all_errors utility in the "accounting.utils.flash_errors" module to recursively flush all form errors in the sub-forms.

src/accounting/utils/flash_errors.py

@@ -0,0 +1,50 @@
+# 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 utility to flash all errors from the forms.
+
+This module should not import any other module from the application.
+
+"""
+import typing as t
+
+from flask import flash
+from flask_wtf import FlaskForm
+
+
+def flash_form_errors(form: FlaskForm) -> None:
+    """Flash all errors from a form recursively.
+
+    :param form: The form.
+    :return: None.
+    """
+    __flash_errors(form.errors)
+
+
+def __flash_errors(error: t.Any) -> None:
+    """Flash all errors recursively.
+
+    :param error: The errors.
+    :return: None.
+    """
+    if isinstance(error, dict):
+        for key in error:
+            __flash_errors(error[key])
+    elif isinstance(error, list):
+        for e in error:
+            __flash_errors(e)
+    else:
+        flash(error, "error")