TMSS-1218: create parsip ref on subtask creation

SAS/TMSS/backend/src/tmss/tmssapp/models/scheduling.py

@@ -125,6 +125,16 @@ class SIPidentifier(Model):
         if model._state.adding:
             model.global_identifier = SIPidentifier.objects.create(source="TMSS")
 
+    @staticmethod
+    def assign_new_parset_id_to_model(model):
+        """
+        Create an Unique Identifier for given model class if model is being created.
+        """
+        if model._state.adding:
+            model.global_parset_identifier = SIPidentifier.objects.create(source="TMSS")
+
+
+
 #
 # Instance Objects
 #
@@ -336,6 +346,7 @@ class Subtask(BasicCommon, ProjectPropertyMixin, TemplateSchemaMixin):
 
         self.annotate_validate_add_defaults_to_doc_using_template('specifications_doc', 'specifications_template')
         SIPidentifier.assign_new_id_to_model(self)
+        SIPidentifier.assign_new_parset_id_to_model(self)
 
         # check for uniqueness of SAP names:
         # todo: this is a very specific check, that depends on the template. On the task level, we have a javascript