Allow email notifications to render a different template

* by temporarily overriding the `notification.type`

invenio_config_tuw/notifications/backends.py

@@ -7,6 +7,8 @@
 
 """Custom notification backends for TU Wien."""
 
+from contextlib import contextmanager
+
 from flask import current_app
 from invenio_mail.tasks import send_email
 from invenio_notifications.backends.email import EmailNotificationBackend
@@ -15,6 +17,24 @@ from marshmallow_utils.html import strip_html
 from ..proxies import current_config_tuw
 
 
+@contextmanager
+def temp_hack_notification_type(notification):
+    """Temporarily override the ``notification.type``.
+
+    This enables notifications built by our custom user/group notification builders
+    to render templates that are not ``{user,group}-notification.jinja``.
+    """
+    old_notif_type = notification.type
+    temp_type = getattr(
+        notification, "template_name", notification.context.get("template_name", None)
+    )
+    if temp_type:
+        notification.type = temp_type.rstrip(".jinja")
+
+    yield notification
+    notification.type = old_notif_type
+
+
 class TUWEmailNotificationBackend(EmailNotificationBackend):
     """Email notification backend extended for the use cases at TU Wien.
 
@@ -24,7 +44,8 @@ class TUWEmailNotificationBackend(EmailNotificationBackend):
 
     def send(self, notification, recipient):
         """Mail sending implementation."""
-        content = self.render_template(notification, recipient)
+        with temp_hack_notification_type(notification):
+            content = self.render_template(notification, recipient)
         subject = content["subject"]
 
         # if a site identifier is configured, we set is as prefix for email subjects

invenio_config_tuw/notifications/builders.py

@@ -27,10 +27,12 @@ class UserNotificationBuilder(NotificationBuilder):
         cls,
         receiver,
         subject,
-        message,
+        message=None,
         html_message=None,
         plain_message=None,
         md_message=None,
+        template_name=None,
+        **kwargs,
     ):
         """Build notification with context."""
         return Notification(
@@ -42,6 +44,8 @@ class UserNotificationBuilder(NotificationBuilder):
                 "html_message": html_message,
                 "plain_message": plain_message,
                 "md_message": md_message,
+                "template_name": template_name,
+                **kwargs,
             },
         )