fix: replace custom duplication logic with signal

For duplicating entities, there was custom logic to copy ManyToManyField
- which was tailored to TempTriples. This had the downside of simply
creating new objects by hand.

This commit introduces a `duplicate` method in the Triple model, which
implements the functionality of duplicating itself and also triggers
pre_- and post_duplicate signals. This has the advantage that instances
that point to the Triple (like References) can also be duplicated using
signals.

apis_core/apis_metainfo/models.py

@@ -95,34 +95,6 @@ def duplicate(self):
         for field in related_fields:
             # we are not using `isinstance` because we want to
             # differentiate between different levels of inheritance
-            if type(field) is ManyToOneRel:
-                # Get a list of fields of the related model that are unique
-                # because `related_field`s do not have a unique attribute
-                # we are using getattr
-                # Either use the related_name or contruct ith from the fields name
-                relname = field.related_name or f"{field.name}_set"
-                # Iterate through the objects in the queryset, get the subclass of the
-                # entry, remove the unique attributes and create a copy of the object.
-                # Then save the copied object
-                # This is limited to models with the objects_inheritance attribute, so
-                # basically it is tailored to TempTriples
-                if getattr(field.related_model, "objects_inheritance", False):
-                    for entry in getattr(self, relname).all():
-                        relmodel = field.related_model
-                        # create a copy based on the subclass
-                        entry_copy = relmodel.objects_inheritance.get_subclass(
-                            id=entry.id
-                        )
-                        model_fields = relmodel._meta.get_fields()
-                        unique_fields = [
-                            f.name for f in model_fields if getattr(f, "unique", False)
-                        ]
-                        for key in unique_fields:
-                            setattr(entry_copy, key, None)
-                        entry_copy.pk = None
-                        entry_copy._state.adding = True
-                        setattr(entry_copy, field.field.name, newobj)
-                        entry_copy.save()
             if type(field) is ForeignKey:
                 setattr(newobj, field.name, getattr(self, field.name))
             if type(field) is ManyToManyField:

apis_core/apis_relations/apps.py

@@ -4,3 +4,6 @@
 class RelationsConfig(AppConfig):
     default_auto_field = "django.db.models.AutoField"
     name = "apis_core.apis_relations"
+
+    def ready(self):
+        from . import signals

apis_core/apis_relations/models.py

@@ -1,4 +1,5 @@
 import unicodedata
+import copy
 
 # from reversion import revisions as reversion
 import reversion
@@ -14,6 +15,7 @@
 # from apis_core.apis_entities.models import Person
 from apis_core.apis_metainfo.models import RootObject
 from apis_core.utils import DateParser
+from apis_core.apis_metainfo import signals
 
 
 def find_if_user_accepted():
@@ -310,6 +312,22 @@ def get_all_childs(cls_current):
 
         super().save(*args, **kwargs)
 
+    def duplicate(self):
+        origin = self.__class__
+        signals.pre_duplicate.send(sender=origin, instance=self)
+
+        instance = copy.copy(self)
+
+        self.pk = None
+        self.id = None
+        self._state.adding = True
+        duplicate = self.save()
+
+        signals.post_duplicate.send(
+            sender=origin, instance=instance, duplicate=duplicate
+        )
+        return duplicate
+
 
 class TempTriple(Triple):
     review = models.BooleanField(

apis_core/apis_relations/signals.py

@@ -0,0 +1,22 @@
+from apis_core.apis_relations.models import TempTriple
+from apis_core.apis_metainfo.models import RootObject
+from apis_core.apis_metainfo.signals import post_duplicate
+from django.dispatch import receiver
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+@receiver(post_duplicate)
+def copy_relations(sender, instance, duplicate, **kwargs):
+    logger.info(f"Copying relations from {instance} to {duplicate}")
+    if isinstance(instance, RootObject):
+        for rel in TempTriple.objects.filter(subj=instance):
+            newrel = rel.duplicate()
+            newrel.subj = duplicate
+            newrel.save()
+        for rel in TempTriple.objects.filter(obj=instance):
+            newrel = rel.duplicate()
+            newrel.obj = duplicate
+            newrel.save()