Ticket #3055: ticket_30500.patch

django/core/management/validation.py

@@ -23 +23 @@
     from django.db.models.loading import get_app_errors
     from django.db.models.fields.related import RelatedObject
     from django.db.models.deletion import SET_NULL, SET_DEFAULT
+    from django.contrib.contenttypes.generic import GenericForeignKey, GenericRelation
 
     e = ModelErrorCollection(outfile)
 
@@ -225 +226 @@
                     "which has not been installed" % (f.name, f.rel.through)
                 )
 
+            elif isinstance(f, GenericRelation):
+                if not any([isinstance(vfield, GenericForeignKey) for vfield in f.rel.to._meta.virtual_fields]):
+                    e.add(opts, "model '%s' must have a GenericForeignKey in order to create a GenericRelation." % f.rel.to.__name__)
+
             rel_opts = f.rel.to._meta
             rel_name = RelatedObject(f.rel.to, cls, f).get_accessor_name()
             rel_query_name = f.related_query_name()

tests/modeltests/invalid_models/models.py

@@ -5 +5 @@
 """
 
 from django.db import models
+from django.contrib.contenttypes import generic
 
 class FieldErrors(models.Model):
     charfield = models.CharField()
@@ -216 +217 @@
 class InvalidSetDefault(models.Model):
     fk = models.ForeignKey('self', on_delete=models.SET_DEFAULT)
 
+class Tag(models.Model):
+   name = models.CharField("name", max_length=20)
 
+class TaggedObject(models.Model):
+   object_id = models.PositiveIntegerField("Object ID")
+   tag = models.ForeignKey(Tag)
+   content_object = generic.GenericForeignKey()
+
+class UserTaggedObject(models.Model):
+   object_tag = models.ForeignKey(TaggedObject)
+
+class ArticleAttachment(models.Model):
+   tags = generic.GenericRelation(TaggedObject)
+   user_tags = generic.GenericRelation(UserTaggedObject)
+
 model_errors = """invalid_models.fielderrors: "charfield": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield2": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield3": CharFields require a "max_length" attribute that is a positive integer.
@@ -324 +339 @@
 invalid_models.nonexistingorderingwithsingleunderscore: "ordering" refers to "does_not_exist", a field that doesn't exist.
 invalid_models.invalidsetnull: 'fk' specifies on_delete=SET_NULL, but cannot be null.
 invalid_models.invalidsetdefault: 'fk' specifies on_delete=SET_DEFAULT, but has no default value.
+invalid_models.articleattachment: model 'UserTaggedObject' must have a GenericForeignKey in order to create a GenericRelation.
 """