Add propagation of fields

ldvspec/lofardata/view_helpers/specification.py

 from typing import List
 
 from django.contrib.auth.models import User
-
 from lofardata.models import Group, WorkSpecification
 
 
@@ -12,26 +11,43 @@ def set_post_submit_values(specification, user):
 
 
 def split_obs_ids_string(obs_ids_string: str) -> List[str]:
-    return [obs_id.strip() for obs_id in obs_ids_string.split(',')]
+    return [obs_id.strip() for obs_id in obs_ids_string.split(",")]
+
 
-def create_work_specifications_for_group(group: Group, created_by: User, obs_ids: List[str], batch_size: int) -> List[WorkSpecification]:
+def create_work_specifications_for_group(
+    group: Group, created_by: User, obs_ids: List[str], batch_size: int
+) -> List[WorkSpecification]:
     work_specs: List[WorkSpecification] = []
 
     for obs_id in obs_ids:
-        work_specs.append(create_work_specification_for_group(group, created_by, obs_id, batch_size))
+        work_specs.append(
+            create_work_specification_for_group(group, created_by, obs_id, batch_size)
+        )
 
     return work_specs
 
-def propagate_group_properties_to_workspecification(group: Group, workspecification: WorkSpecification):
+
+def propagate_group_properties_to_workspecification(
+    group: Group, workspecification: WorkSpecification
+):
     workspecification.processing_site = group.processing_site
     workspecification.selected_workflow = group.selected_workflow
     workspecification.selected_workflow_tag = group.selected_workflow_tag
 
-def create_work_specification_for_group(group: Group, created_by: User, obs_id: str, batch_size: int) -> WorkSpecification:
+    # A WorkSpecification can not be it's own predecessor
+    if workspecification is not group.predecessor_specification:
+        workspecification.predecessor_specification = group.predecessor_specification
+
+    for filter_field in ["dataproduct_type", "activity", "project", "location"]:
+        if group.filters is not None and filter_field in group.filters:
+            workspecification.filters[filter_field] = group.filters[filter_field]
+
+
+def create_work_specification_for_group(
+    group: Group, created_by: User, obs_id: str, batch_size: int
+) -> WorkSpecification:
     workspecification = WorkSpecification(
-        filters={"obs_id": obs_id},
-        group=group,
-        batch_size=batch_size
+        filters={"obs_id": obs_id}, group=group, batch_size=batch_size
     )
 
     propagate_group_properties_to_workspecification(group, workspecification)