Support sending messages when a rule no longer matches and fix dual-use notification sender

core/forms.py

@@ -108,6 +108,7 @@ class NotificationRuleForm(RestrictedFormMixin, ModelForm):
             "topic",
             "url",
             "service",
+            "send_empty",
             "enabled",
         )
         help_texts = {
@@ -121,6 +122,7 @@ class NotificationRuleForm(RestrictedFormMixin, ModelForm):
             "interval": "How often to run the search. On demand evaluates messages as they are received, without running a scheduled search. The remaining options schedule a search of the database with the window below.",
             "window": "Time window to search: 1d, 1h, 1m, 1s, etc.",
             "amount": "Amount of matches to be returned for scheduled queries. Cannot be used with on-demand queries.",
+            "send_empty": "Send a notification if no matches are found.",
         }
 
     def clean(self):