Support assoc. proxies in relationship endpoints

flask_restless/helpers.py

@@ -65,6 +65,35 @@ def session_query(session, model):
     return session.query(model)
 
 
+# TODO Combine this function with the one below.
+def scalar_collection_proxied_relations(model):
+    """Yields the name of each relationship proxied to a scalar collection.
+
+    This includes each relationship to an association table for which
+    there is an association proxy that presents a scalar collection (for
+    example, a list of strings).
+
+    .. seealso::
+
+       :func:`assoc_proxy_scalar_collections`
+          Yields the names of association proxies for the relationships
+          found by this function.
+
+    .. versionadded:: 1.0.0
+
+    """
+    mapper = sqlalchemy_inspect(model)
+    for k, v in mapper.all_orm_descriptors.items():
+        if isinstance(v, AssociationProxy):
+            # HACK SQLAlchemy only loads the association proxy
+            # on-demand. We need to call `hasattr` in order to force
+            # SQLAlchemy to load the attribute.
+            hasattr(model, k)
+            if not isinstance(v.remote_attr.property, RelationshipProperty):
+                if is_like_list(model, v.local_attr.key):
+                    yield v.local_attr.key
+
+
 def assoc_proxy_scalar_collections(model):
     """Yields the name of each association proxy collection as a string.
 
@@ -76,7 +105,7 @@ def assoc_proxy_scalar_collections(model):
 
     .. seealso::
 
-       :func:`assoc_proxy_inst_collections`
+       :func:`scalar_collection_proxied_relations`
 
     .. versionadded:: 1.0.0
 

flask_restless/views/relationships.py

@@ -20,6 +20,7 @@
 from flask import request
 from werkzeug.exceptions import BadRequest
 
+from ..helpers import scalar_collection_proxied_relations
 from ..helpers import collection_name
 from ..helpers import get_by
 from ..helpers import get_related_model
@@ -93,6 +94,14 @@ def get(self, resource_id, relation_name):
         if primary_resource is None:
             detail = 'No resource with ID {0}'.format(resource_id)
             return error_response(404, detail=detail)
+        # Check if the relation is to an association table through which
+        # there is an association proxy that proxies to a scalar
+        # collection. In this situation, we wish to hide the
+        # relationship entirely, since the scalar collection is exposed
+        # as an attribute.
+        if relation_name in scalar_collection_proxied_relations(self.model):
+            detail = 'No relationship named {0}'.format(relation_name)
+            return error_response(404, detail=detail)
         if is_like_list(primary_resource, relation_name):
             try:
                 filters, sort, group_by, single = \
@@ -225,6 +234,14 @@ def patch(self, resource_id, relation_name):
             detail = 'Model {0} has no relation named {1}'
             detail = detail.format(self.model, relation_name)
             return error_response(404, detail=detail)
+        # Check if the relation is to an association table through which
+        # there is an association proxy that proxies to a scalar
+        # collection. In this situation, we wish to hide the
+        # relationship entirely, since the scalar collection is exposed
+        # as an attribute.
+        if relation_name in scalar_collection_proxied_relations(self.model):
+            detail = 'No relationship named {0}'.format(relation_name)
+            return error_response(404, detail=detail)
         related_model = get_related_model(self.model, relation_name)
         # related_value = getattr(instance, relation_name)
 
@@ -342,6 +359,14 @@ def delete(self, resource_id, relation_name):
                 resource_id = temp_result
         instance = get_by(self.session, self.model, resource_id,
                           self.primary_key)
+        # Check if the relation is to an association table through which
+        # there is an association proxy that proxies to a scalar
+        # collection. In this situation, we wish to hide the
+        # relationship entirely, since the scalar collection is exposed
+        # as an attribute.
+        if relation_name in scalar_collection_proxied_relations(self.model):
+            detail = 'No relationship named {0}'.format(relation_name)
+            return error_response(404, detail=detail)
         # If no such relation exists, return an error to the client.
         if not hasattr(instance, relation_name):
             detail = 'No such link: {0}'.format(relation_name)

tests/test_associationproxy.py

@@ -293,15 +293,15 @@ def test_fetching(self):
         self.manager.create_api(self.Article)
 
         article = self.Article(id=1)
-        article.tag_names = ['foo', 'bar']
+        article.tag_names = [u'foo', u'bar']
         self.session.add(article)
         self.session.commit()
 
         response = self.app.get('/api/article/1')
         document = loads(response.data)
         article = document['data']
         tag_names = sorted(article['attributes']['tag_names'])
-        self.assertEqual(tag_names, ['bar', 'foo'])
+        self.assertEqual(tag_names, [u'bar', u'foo'])
 
     def test_creating(self):
         """Tests for creating with an association proxy to a scalar list."""
@@ -311,7 +311,7 @@ def test_creating(self):
             'data': {
                 'type': 'article',
                 'attributes': {
-                    'tag_names': ['foo', 'bar']
+                    'tag_names': [u'foo', u'bar']
                 }
             }
         }
@@ -321,19 +321,19 @@ def test_creating(self):
         # Check that the response includes the `tag_names` attribute.
         document = loads(response.data)
         article = document['data']
-        self.assertEqual(article['attributes']['tag_names'], ['foo', 'bar'])
+        self.assertEqual(article['attributes']['tag_names'], [u'foo', u'bar'])
 
         # Check that the Article object has been created and has the tag names.
         self.assertEqual(self.session.query(self.Article).count(), 1)
         article = self.session.query(self.Article).first()
-        self.assertEqual(article.tag_names, ['foo', 'bar'])
+        self.assertEqual(article.tag_names, [u'foo', u'bar'])
 
     def test_updating(self):
         """Tests for updating an association proxy to a scalar list."""
         self.manager.create_api(self.Article, methods=['PATCH'])
 
         article = self.Article(id=1)
-        article.tag_names = ['foo', 'bar']
+        article.tag_names = [u'foo', u'bar']
         self.session.add(article)
         self.session.commit()
 
@@ -342,20 +342,20 @@ def test_updating(self):
                 'type': 'article',
                 'id': '1',
                 'attributes': {
-                    'tag_names': ['baz', 'xyzzy']
+                    'tag_names': [u'baz', u'xyzzy']
                 }
             }
         }
         response = self.app.patch('/api/article/1', data=dumps(data))
         self.assertEqual(response.status_code, 204)
-        self.assertEqual(article.tag_names, ['baz', 'xyzzy'])
+        self.assertEqual(article.tag_names, [u'baz', u'xyzzy'])
 
     def test_deleting(self):
         """Test for deleting a resource with a to-many relationship."""
         self.manager.create_api(self.Article, methods=['DELETE'])
 
         article = self.Article(id=1)
-        article.tag_names = ['foo', 'bar']
+        article.tag_names = [u'foo', u'bar']
         self.session.add(article)
         self.session.commit()
 
@@ -368,24 +368,22 @@ def test_deleting(self):
         response = self.app.delete('/api/article/1', data=dumps(data))
         self.assertEqual(response.status_code, 204)
         tags = self.session.query(self.Tag).all()
-        self.assertEqual(['bar', 'foo'], sorted(tag.name for tag in tags))
+        self.assertEqual([u'bar', u'foo'], sorted(tag.name for tag in tags))
 
     def test_fetch_relationships(self):
         """Test for fetching to-many relationship resource identifiers."""
         self.manager.create_api(self.Article)
         self.manager.create_api(self.Tag)
 
         article = self.Article(id=1)
-        article.tag_names = ['foo', 'bar']
+        article.tag_names = [u'foo', u'bar']
         self.session.add(article)
         self.session.commit()
 
-        # TODO What to do about this situation? The `tags` relationship
-        # is not shown in the resource representation of the Article
-        # object because we assume the `tag_names` attribute is the only
-        # thing the user wants to expose. However, the Tag objects
-        # underlying the `tag_names` are visible in the relationships
-        # attribute.
+        # The `tags` relationship is not shown in the resource
+        # representation of the Article object because we assume the
+        # `tag_names` attribute is the only thing the user wants to
+        # expose.
         response = self.app.get('/api/article/1/relationships/tags')
         self.assertEqual(response.status_code, 404)
 
@@ -398,13 +396,10 @@ def test_adding_to_relationship(self):
         self.session.add(article)
         self.session.commit()
 
-        # TODO What to do about this situation? The `tags` relationship
-        # is not shown in the resource representation of the Article
-        # object because we assume the `tag_names` attribute is the only
-        # thing the user wants to expose. However, the Tag objects
-        # underlying the `tag_names` are visible in the relationships
-        # attribute. Maybe we shouldn't actually hide the `tags`
-        # relationship.
+        # The `tags` relationship is not shown in the resource
+        # representation of the Article object because we assume the
+        # `tag_names` attribute is the only thing the user wants to
+        # expose.
         data = {
             'data': [
                 {'type': 'tag', 'id': '1'},
@@ -427,13 +422,10 @@ def test_removing_from_relationship(self):
         self.session.add_all([article, tag])
         self.session.commit()
 
-        # TODO What to do about this situation? The `tags` relationship
-        # is not shown in the resource representation of the Article
-        # object because we assume the `tag_names` attribute is the only
-        # thing the user wants to expose. However, the Tag objects
-        # underlying the `tag_names` are visible in the relationships
-        # attribute. Maybe we shouldn't actually hide the `tags`
-        # relationship.
+        # The `tags` relationship is not shown in the resource
+        # representation of the Article object because we assume the
+        # `tag_names` attribute is the only thing the user wants to
+        # expose.
         data = {
             'data': [
                 {'type': 'tag', 'id': '1'},
@@ -456,13 +448,10 @@ def test_replacing_relationship(self):
         self.session.add_all([article, tag1, tag2])
         self.session.commit()
 
-        # TODO What to do about this situation? The `tags` relationship
-        # is not shown in the resource representation of the Article
-        # object because we assume the `tag_names` attribute is the only
-        # thing the user wants to expose. However, the Tag objects
-        # underlying the `tag_names` are visible in the relationships
-        # attribute. Maybe we shouldn't actually hide the `tags`
-        # relationship.
+        # The `tags` relationship is not shown in the resource
+        # representation of the Article object because we assume the
+        # `tag_names` attribute is the only thing the user wants to
+        # expose.
         data = {
             'data': [
                 {'type': 'tag', 'id': '2'},