Add notification signal (Z:#23127501) (#3725)

* Add and send signal for refund requests

* Add and send signal for notifications

* Revert changes

* Fix typo

Co-authored-by: Mira <weller@rami.io>

* Document parameters

---------

Co-authored-by: Mira <weller@rami.io>

src/pretix/base/services/notifications.py

@@ -30,6 +30,7 @@ from pretix.base.models import LogEntry, NotificationSetting, User
 from pretix.base.notifications import Notification, get_all_notification_types
 from pretix.base.services.mail import mail_send_task
 from pretix.base.services.tasks import ProfiledTask, TransactionAwareTask
+from pretix.base.signals import notification
 from pretix.celery_app import app
 from pretix.helpers.urls import build_absolute_uri
 
@@ -90,6 +91,8 @@ def notify(logentry_ids: list):
             if enabled and um not in notify_specific:
                 send_notification.apply_async(args=(logentry.id, notification_type.action_type, user.pk, method))
 
+        notification.send(logentry.event, logentry_id=logentry.id, notification_type=notification_type.action_type)
+
 
 @app.task(base=ProfiledTask, acks_late=True, max_retries=9, default_retry_delay=900)
 def send_notification(logentry_id: int, action_type: str, user_id: int, method: str):

src/pretix/base/signals.py

@@ -279,6 +279,15 @@ however for this signal, the ``sender`` **may also be None** to allow creating t
 notification settings!
 """
 
+notification = EventPluginSignal()
+"""
+Arguments: ``logentry_id``, ``notification_type``
+
+This signal is sent out when a notification is sent.
+
+As with all event-plugin signals, the ``sender`` keyword argument will contain the event.
+"""
+
 register_sales_channels = django.dispatch.Signal()
 """
 This signal is sent out to get all known sales channels types. Receivers should return an