Add /language/<language> route for changing the locale using a session variable

core/admin/mailu/ui/views/__init__.py

@@ -1,4 +1,4 @@
 __all__ = [
     'admins', 'aliases', 'alternatives', 'base', 'domains', 'fetches',
-    'managers', 'users', 'relays', 'tokens'
+    'managers', 'users', 'relays', 'tokens', 'languages'
 ]

core/admin/mailu/ui/views/languages.py

@@ -0,0 +1,9 @@
+from mailu.ui import ui, forms, access
+
+import flask
+
+
+@ui.route('/language/<language>', methods=['GET'])
+def set_language(language=None):
+    flask.session['language'] = language
+    return flask.redirect(flask.url_for('.user_settings'))

core/admin/mailu/utils.py

@@ -27,10 +27,17 @@ babel = flask_babel.Babel()
 
 @babel.localeselector
 def get_locale():
+    try:
+        language = flask.session['language']
+    except KeyError:
+        language = None
+
+    if language is not None:
+        return language
+
     translations = list(map(str, babel.list_translations()))
     return flask.request.accept_languages.best_match(translations)
 
-
 # Proxy fixer
 class PrefixMiddleware(object):
     def __call__(self, environ, start_response):