add new should_udpate func [SDCP-742] (#1963)

* add new should_udpate func [SDCP-742]

* update params

* refactore logic

server/planning/events/events.py

@@ -797,6 +797,15 @@ def delete_event_files(self, updates, original):
             if events_using_file.count() == 0:
                 files_service.delete_action(lookup={"_id": file})
 
+    def should_update(self, old_item, new_item, provider):
+        return old_item is None or not any(
+            [
+                old_item.get("version_creator"),
+                old_item.get("pubstatus") == "cancelled",
+                old_item.get("state") == "killed",
+            ]
+        )
+
 
 class EventsResource(superdesk.Resource):
     """Resource for events data model

server/planning/planning/planning.py

@@ -257,6 +257,9 @@ def on_duplicated(self, doc, parent_id):
     def on_locked_planning(self, item, user_id):
         self.generate_related_assignments([item])
 
+    def should_update(self, old_item, new_item, provider):
+        return True
+
     @staticmethod
     def set_ingest_provider_sequence(item, provider):
         """Sets the value of ingest_provider_sequence in item.