Basic babel integration for Flask.

src/tjts5901/app.py

@@ -22,6 +22,7 @@ from flask import (
 
 from .utils import get_version
 from .db import init_db
+from .i18n import init_babel
 
 logger = logging.getLogger(__name__)
 
@@ -55,6 +56,9 @@ def create_app(config: Optional[Dict] = None) -> Flask:
     except OSError:
         pass
 
+    # Initialize the Flask-Babel extension.
+    init_babel(flask_app)
+
     # Initialize the database connection.
     init_db(flask_app)
 

src/tjts5901/i18n.py

+"""
+Internationalisation and localisation support for the application.
+"""
+from flask_babel import Babel
+from babel import Locale
+from babel import __version__ as babel_version
+from flask import Flask
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def init_babel(flask_app: Flask):
+    """
+    Initialize the Flask-Babel extension.
+    """
+
+    # Configure the Flask-Babel extension.
+    # Try setting the default locale from underlying OS. Falls back into English.
+    system_language = Locale.default().language
+    flask_app.config.setdefault("BABEL_DEFAULT_LOCALE", system_language)
+
+    # TODO: Set the default timezone from underlying OS.
+
+    babel = Babel(flask_app)
+
+    logger.info("Initialized Flask-Babel extension %s.", babel_version,
+                extra=flask_app.config.get_namespace("BABEL_"))
+    return babel