added tests and documentation for representing a reverse GenericRelation

tastypie/fields.py

@@ -697,6 +697,10 @@ class ToManyField(RelatedField):
     Note that the ``hydrate`` portions of this field are quite different than
     any other field. ``hydrate_m2m`` actually handles the data and relations.
     This is due to the way Django implements M2M relationships.
+    
+    Can be used to represent a ``GenericRelation`` 
+    (reverse of ``GenericForeignKey``).  Simply set ``to`` to the resource 
+    which represents the other end of the relation.
     """
     is_m2m = True
     help_text = 'Many related resources. Can be either a list of URIs or list of individually nested resource data.'

tests/related_resource/api/resources.py

@@ -24,7 +24,7 @@ class Meta:
 
 class CategoryResource(ModelResource):
     parent = fields.ToOneField('self', 'parent', null=True)
-
+    tags = fields.ToManyField('related_resource.api.resources.GenericTagResource', attribute="tags", null=True, blank=True)
     class Meta:
         resource_name = 'category'
         queryset = Category.objects.all()

tests/related_resource/models.py

@@ -5,7 +5,7 @@
 class Category(models.Model):
     parent = models.ForeignKey('self', null=True)
     name = models.CharField(max_length=32)
-
+    tags = generic.GenericRelation('related_resource.GenericTag')
     def __unicode__(self):
         return u"%s (%s)" % (self.name, self.parent)
 

tests/related_resource/tests.py

@@ -391,4 +391,43 @@ def test_put(self):
                     ContentType.objects.get_for_model(Taggable))))
         resp = resource.put_detail(request, pk=data['id'])
         self.assertEqual(resp.status_code, 204)
-        self.assertEqual(GenericTag.objects.get(pk=data['id']).content_type, ContentType.objects.get_for_model(Taggable))
+        self.assertEqual(GenericTag.objects.get(pk=data['id']).content_type, ContentType.objects.get_for_model(Taggable))
+
+    def test_reverse(self):
+        tags = self.category_1.tags.all()
+
+        request = MockRequest()
+        request.GET = {'format': 'json'}
+        request.method = 'GET'
+
+        resource = api.canonical_resource_for('generictag')
+        resource.fields['content_object'].full = False
+        # should get us self.tag_1
+        resp = resource.wrap_view('dispatch_detail')(request, pk=self.tag_1.pk)
+        self.assertEqual(resp.status_code, 200)
+        data = json.loads(resp.content)
+        # test that the uri for content_object pointed to self.category_1
+        self.assertEqual(data['content_object'], 
+                        CategoryResource().get_resource_uri(self.category_1))
+
+        resp = self.client.get(data['content_object'], data={"format": "json"})
+        self.assertEqual(resp.status_code, 200)
+        data = json.loads(resp.content)
+        tags_urls = list()
+        for tag in tags:
+            tags_urls.append(GenericTagResource().get_resource_uri(tag))
+        self.assertEqual(data['tags'], tags_urls)
+
+        # add some more tags to this category
+        GenericTag.objects.create(name="Object Orientated", content_object=self.category_1)
+        GenericTag.objects.create(name="Interpreted", content_object=self.category_1)
+
+        tags = self.category_1.tags.all()
+        tags_urls = list()
+        for tag in tags:
+            tags_urls.append(GenericTagResource().get_resource_uri(tag))
+
+        resp = self.client.get(data['resource_uri'], data={"format": "json"})
+        self.assertEqual(resp.status_code, 200)
+        data = json.loads(resp.content)
+        self.assertEqual(data['tags'], tags_urls)