Merge pull request #237 from Globegitter/connection-fields-object-types

Allow ConnectionFields to have ObjectTypes as per relay spec

graphene/contrib/django/types.py

@@ -4,7 +4,8 @@ import six
 from django.db import models
 
 from ...core.classtypes.objecttype import ObjectType, ObjectTypeMeta
-from ...relay.types import Connection, Node, NodeMeta
+from ...relay.types import Node, NodeMeta
+from ...relay.connection import Connection
 from .converter import convert_django_field_with_choices
 from .options import DjangoOptions
 from .utils import get_reverse_fields

graphene/contrib/sqlalchemy/types.py

@@ -5,7 +5,8 @@ from sqlalchemy.inspection import inspect as sqlalchemyinspect
 from sqlalchemy.orm.exc import NoResultFound
 
 from ...core.classtypes.objecttype import ObjectType, ObjectTypeMeta
-from ...relay.types import Connection, Node, NodeMeta
+from ...relay.types import Node, NodeMeta
+from ...relay.connection import Connection
 from .converter import (convert_sqlalchemy_column,
                         convert_sqlalchemy_relationship)
 from .options import SQLAlchemyOptions

graphene/relay/__init__.py

@@ -6,12 +6,15 @@ from .fields import (
 
 from .types import (
     Node,
-    PageInfo,
-    Edge,
-    Connection,
     ClientIDMutation
 )
 
+from .connection import (
+    PageInfo,
+    Connection,
+    Edge,
+)
+
 from .utils import is_node
 
 __all__ = ['ConnectionField', 'NodeField', 'GlobalIDField', 'Node',

graphene/relay/connection.py

@@ -0,0 +1,87 @@
+from collections import Iterable
+
+from graphql_relay.connection.arrayconnection import connection_from_list
+
+from ..core.classtypes import ObjectType
+from ..core.types import Field, Boolean, String, List
+from ..utils import memoize
+
+
+class PageInfo(ObjectType):
+
+    def __init__(self, start_cursor="", end_cursor="",
+                 has_previous_page=False, has_next_page=False, **kwargs):
+        super(PageInfo, self).__init__(**kwargs)
+        self.startCursor = start_cursor
+        self.endCursor = end_cursor
+        self.hasPreviousPage = has_previous_page
+        self.hasNextPage = has_next_page
+
+    hasNextPage = Boolean(
+        required=True,
+        description='When paginating forwards, are there more items?')
+    hasPreviousPage = Boolean(
+        required=True,
+        description='When paginating backwards, are there more items?')
+    startCursor = String(
+        description='When paginating backwards, the cursor to continue.')
+    endCursor = String(
+        description='When paginating forwards, the cursor to continue.')
+
+
+class Edge(ObjectType):
+    '''An edge in a connection.'''
+    cursor = String(
+        required=True, description='A cursor for use in pagination')
+
+    @classmethod
+    @memoize
+    def for_node(cls, node):
+        node_field = Field(node, description='The item at the end of the edge')
+        return type(
+            '%s%s' % (node._meta.type_name, cls._meta.type_name),
+            (cls,),
+            {'node_type': node, 'node': node_field})
+
+
+class Connection(ObjectType):
+    '''A connection to a list of items.'''
+
+    def __init__(self, edges, page_info, **kwargs):
+        super(Connection, self).__init__(**kwargs)
+        self.edges = edges
+        self.pageInfo = page_info
+
+    class Meta:
+        type_name = 'DefaultConnection'
+
+    pageInfo = Field(PageInfo, required=True,
+                     description='The Information to aid in pagination')
+
+    _connection_data = None
+
+    @classmethod
+    @memoize
+    def for_node(cls, node, edge_type=None):
+        edge_type = edge_type or Edge.for_node(node)
+        edges = List(edge_type, description='Information to aid in pagination.')
+        return type(
+            '%s%s' % (node._meta.type_name, cls._meta.type_name),
+            (cls,),
+            {'edge_type': edge_type, 'edges': edges})
+
+    @classmethod
+    def from_list(cls, iterable, args, context, info):
+        assert isinstance(
+            iterable, Iterable), 'Resolved value from the connection field have to be iterable'
+        connection = connection_from_list(
+            iterable, args, connection_type=cls,
+            edge_type=cls.edge_type, pageinfo_type=PageInfo)
+        connection.set_connection_data(iterable)
+        return connection
+
+    def set_connection_data(self, data):
+        self._connection_data = data
+
+    def get_connection_data(self):
+        return self._connection_data

graphene/relay/fields.py

@@ -6,6 +6,7 @@ from ..core.fields import Field
 from ..core.types.definitions import NonNull
 from ..core.types.scalars import ID, Int, String
 from ..utils.wrap_resolver_function import has_context, with_context
+from .connection import Connection, Edge
 
 
 class ConnectionField(Field):
@@ -23,8 +24,8 @@ class ConnectionField(Field):
             last=Int(),
             description=description,
             **kwargs)
-        self.connection_type = connection_type
-        self.edge_type = edge_type
+        self.connection_type = connection_type or Connection
+        self.edge_type = edge_type or Edge
 
     @with_context
     def resolver(self, instance, args, context, info):
@@ -37,7 +38,7 @@ class ConnectionField(Field):
         else:
             resolved = super(ConnectionField, self).resolver(instance, args, info)
 
-        if isinstance(resolved, connection_type):
+        if isinstance(resolved, self.connection_type):
             return resolved
         return self.from_list(connection_type, resolved, args, context, info)
 
@@ -45,19 +46,14 @@ class ConnectionField(Field):
         return connection_type.from_list(resolved, args, context, info)
 
     def get_connection_type(self, node):
-        connection_type = self.connection_type or node.get_connection_type()
-        edge_type = self.get_edge_type(node)
-        return connection_type.for_node(node, edge_type=edge_type)
+        return self.connection_type.for_node(node)
 
     def get_edge_type(self, node):
-        edge_type = self.edge_type or node.get_edge_type()
-        return edge_type.for_node(node)
+        return self.edge_type.for_node(node)
 
     def get_type(self, schema):
-        from graphene.relay.utils import is_node
         type = schema.T(self.type)
         node = schema.objecttype(type)
-        assert is_node(node), 'Only nodes have connections.'
         schema.register(node)
         connection_type = self.get_connection_type(node)
 

graphene/relay/tests/test_query.py

@@ -19,6 +19,9 @@ class MyNode(relay.Node):
     def get_node(cls, id, info):
         return MyNode(id=id, name='mo')
 
+class MyObject(graphene.ObjectType):
+    name = graphene.String()
+
 
 class SpecialNode(relay.Node):
     value = graphene.String()
@@ -29,6 +32,9 @@ class SpecialNode(relay.Node):
         value = "!!!" if context.get('is_special') else "???"
         return SpecialNode(id=id, value=value)
 
+def _create_my_node_edge(myNode):
+    edge_type = relay.Edge.for_node(MyNode)
+    return edge_type(node=myNode, cursor=str(myNode.id))
 
 class Query(graphene.ObjectType):
     my_node = relay.NodeField(MyNode)
@@ -40,6 +46,12 @@ class Query(graphene.ObjectType):
     context_nodes = relay.ConnectionField(
         MyNode, connection_type=MyConnection, customArg=graphene.String())
 
+    connection_type_nodes = relay.ConnectionField(
+        MyNode, connection_type=MyConnection)
+
+    all_my_objects = relay.ConnectionField(
+        MyObject, connection_type=MyConnection)
+
     def resolve_all_my_nodes(self, args, info):
         custom_arg = args.get('customArg')
         assert custom_arg == "1"
@@ -51,6 +63,16 @@ class Query(graphene.ObjectType):
         assert custom_arg == "1"
         return [MyNode(name='my')]
 
+    def resolve_connection_type_nodes(self, args, info):
+        edges = [_create_my_node_edge(n) for n in [MyNode(id='1', name='my')]]
+        connection_type = MyConnection.for_node(MyNode)
+
+        return connection_type(
+            edges=edges, page_info=relay.PageInfo(has_next_page=True))
+
+    def resolve_all_my_objects(self, args, info):
+        return [MyObject(name='my_object')]
+
 schema.query = Query
 
 
@@ -135,6 +157,74 @@ def test_connectionfield_context_query():
     assert result.data == expected
 
 
+def test_connectionfield_resolve_returns_connection_type_directly():
+    query = '''
+    query RebelsShipsQuery {
+      connectionTypeNodes {
+        edges {
+          node {
+            name
+          }
+        },
+        myCustomField
+        pageInfo {
+          hasNextPage
+        }
+      }
+    }
+    '''
+    expected = {
+        'connectionTypeNodes': {
+            'edges': [{
+                'node': {
+                    'name': 'my'
+                }
+            }],
+            'myCustomField': 'Custom',
+            'pageInfo': {
+                'hasNextPage': True,
+            }
+        }
+    }
+    result = schema.execute(query)
+    assert not result.errors
+    assert result.data == expected
+
+
+def test_connectionfield_resolve_returning_objects():
+    query = '''
+    query RebelsShipsQuery {
+      allMyObjects {
+        edges {
+          node {
+            name
+          }
+        },
+        myCustomField
+        pageInfo {
+          hasNextPage
+        }
+      }
+    }
+    '''
+    expected = {
+        'allMyObjects': {
+            'edges': [{
+                'node': {
+                    'name': 'my_object'
+                }
+            }],
+            'myCustomField': 'Custom',
+            'pageInfo': {
+                'hasNextPage': False,
+            }
+        }
+    }
+    result = schema.execute(query)
+    assert not result.errors
+    assert result.data == expected
+
+
 @pytest.mark.parametrize('specialness,value', [(True, '!!!'), (False, '???')])
 def test_get_node_info(specialness, value):
     query = '''

graphene/relay/types.py

@@ -1,108 +1,21 @@
 import inspect
 import warnings
-from collections import Iterable
 from functools import wraps
 
 import six
 
-from graphql_relay.connection.arrayconnection import connection_from_list
 from graphql_relay.node.node import to_global_id
 
-from ..core.classtypes import InputObjectType, Interface, Mutation, ObjectType
+from ..core.classtypes import InputObjectType, Interface, Mutation
 from ..core.classtypes.interface import InterfaceMeta
 from ..core.classtypes.mutation import MutationMeta
-from ..core.types import Boolean, Field, List, String
+from ..core.types import String
 from ..core.types.argument import ArgumentsGroup
 from ..core.types.definitions import NonNull
-from ..utils import memoize
 from ..utils.wrap_resolver_function import has_context, with_context
 from .fields import GlobalIDField
 
 
-class PageInfo(ObjectType):
-
-    def __init__(self, start_cursor="", end_cursor="",
-                 has_previous_page=False, has_next_page=False, **kwargs):
-        super(PageInfo, self).__init__(**kwargs)
-        self.startCursor = start_cursor
-        self.endCursor = end_cursor
-        self.hasPreviousPage = has_previous_page
-        self.hasNextPage = has_next_page
-
-    hasNextPage = Boolean(
-        required=True,
-        description='When paginating forwards, are there more items?')
-    hasPreviousPage = Boolean(
-        required=True,
-        description='When paginating backwards, are there more items?')
-    startCursor = String(
-        description='When paginating backwards, the cursor to continue.')
-    endCursor = String(
-        description='When paginating forwards, the cursor to continue.')
-
-
-class Edge(ObjectType):
-    '''An edge in a connection.'''
-    cursor = String(
-        required=True, description='A cursor for use in pagination')
-
-    @classmethod
-    @memoize
-    def for_node(cls, node):
-        from graphene.relay.utils import is_node
-        assert is_node(node), 'ObjectTypes in a edge have to be Nodes'
-        node_field = Field(node, description='The item at the end of the edge')
-        return type(
-            '%s%s' % (node._meta.type_name, cls._meta.type_name),
-            (cls,),
-            {'node_type': node, 'node': node_field})
-
-
-class Connection(ObjectType):
-    '''A connection to a list of items.'''
-
-    def __init__(self, edges, page_info, **kwargs):
-        super(Connection, self).__init__(**kwargs)
-        self.edges = edges
-        self.pageInfo = page_info
-
-    class Meta:
-        type_name = 'DefaultConnection'
-
-    pageInfo = Field(PageInfo, required=True,
-                     description='The Information to aid in pagination')
-
-    _connection_data = None
-
-    @classmethod
-    @memoize
-    def for_node(cls, node, edge_type=None):
-        from graphene.relay.utils import is_node
-        edge_type = edge_type or Edge.for_node(node)
-        assert is_node(node), 'ObjectTypes in a connection have to be Nodes'
-        edges = List(edge_type, description='Information to aid in pagination.')
-        return type(
-            '%s%s' % (node._meta.type_name, cls._meta.type_name),
-            (cls,),
-            {'edge_type': edge_type, 'edges': edges})
-
-    @classmethod
-    def from_list(cls, iterable, args, context, info):
-        assert isinstance(
-            iterable, Iterable), 'Resolved value from the connection field have to be iterable'
-        connection = connection_from_list(
-            iterable, args, connection_type=cls,
-            edge_type=cls.edge_type, pageinfo_type=PageInfo)
-        connection.set_connection_data(iterable)
-        return connection
-
-    def set_connection_data(self, data):
-        self._connection_data = data
-
-    def get_connection_data(self):
-        return self._connection_data
-
-
 class NodeMeta(InterfaceMeta):
 
     def construct_get_node(cls):
@@ -153,17 +66,6 @@ class Node(six.with_metaclass(NodeMeta, Interface)):
     def to_global_id(self):
         return self.global_id(self.id)
 
-    connection_type = Connection
-    edge_type = Edge
-
-    @classmethod
-    def get_connection_type(cls):
-        return cls.connection_type
-
-    @classmethod
-    def get_edge_type(cls):
-        return cls.edge_type
-
 
 class MutationInputType(InputObjectType):
     clientMutationId = String(required=True)