Improved relay resolvers

Author: syrusakbary

graphene/core/fields.py

@@ -73,8 +73,7 @@ def get_resolve_fn(self):
 
                 @wraps(resolve_fn)
                 def custom_resolve_fn(instance, args, info):
-                    custom_fn = getattr(instance, custom_resolve_fn_name)
-                    return custom_fn(args, info)
+                    return resolve_fn(instance, args, info)
                 return custom_resolve_fn
 
     def get_object_type(self, schema):

graphene/core/options.py

@@ -1,5 +1,5 @@
 from graphene.utils import cached_property
-from collections import OrderedDict
+from collections import OrderedDict, namedtuple
 
 DEFAULT_NAMES = ('description', 'name', 'interface',
                  'type_name', 'interfaces', 'proxy')
@@ -59,6 +59,10 @@ def contribute_to_class(self, cls, name):
 
         del self.meta
 
+    @cached_property
+    def object(self):
+        return namedtuple(self.type_name, self.fields_map.keys())
+
     def add_field(self, field):
         self.local_fields.append(field)
 

graphene/core/types.py

@@ -113,17 +113,23 @@ def add_to_class(cls, name, value):
 
 class BaseObjectType(object):
 
-    def __new__(cls, instance=None, *args, **kwargs):
+    def __new__(cls, instance=None, **kwargs):
         if cls._meta.interface:
             raise Exception("An interface cannot be initialized")
         if instance is None:
-            return None
+            if not kwargs:
+                return None
         elif type(instance) is cls:
             instance = instance.instance
-        return super(BaseObjectType, cls).__new__(cls, *args, **kwargs)
 
-    def __init__(self, instance):
+        return super(BaseObjectType, cls).__new__(cls)
+
+    def __init__(self, instance=None, **kwargs):
         signals.pre_init.send(self.__class__, instance=instance)
+        assert instance or kwargs
+        if not instance:
+            init_kwargs = dict({k: None for k in self._meta.fields_map.keys()}, **kwargs)
+            instance = self._meta.object(**init_kwargs)
         self.instance = instance
         signals.post_init.send(self.__class__, instance=self)
 

graphene/relay/fields.py

@@ -4,7 +4,7 @@
     connection_from_list
 )
 from graphql_relay.connection.connection import (
-    connectionArgs
+    connection_args
 )
 from graphql_relay.node.node import (
     from_global_id
@@ -21,35 +21,54 @@
 
 class ConnectionField(Field):
 
-    def __init__(self, field_type, resolve=None, description='', connection_type=None, edge_type=None, **kwargs):
-        from graphene.relay.types import Connection, Edge
+    def __init__(self, field_type, resolve=None, description='',
+                 connection_type=None, edge_type=None, **kwargs):
         super(ConnectionField, self).__init__(field_type, resolve=resolve,
-                                              args=connectionArgs, description=description, **kwargs)
-        self.connection_type = connection_type or Connection
-        self.edge_type = edge_type or Edge
-        assert issubclass(self.connection_type, Connection), 'connection_type in %r must be a subclass of Connection' % self
-        assert issubclass(self.edge_type, Edge), 'edge_type in %r must be a subclass of Edge' % self
+                                              args=connection_args,
+                                              description=description, **kwargs)
+        self.connection_type = connection_type
+        self.edge_type = edge_type
 
     def wrap_resolved(self, value, instance, args, info):
         return value
 
     def resolve(self, instance, args, info):
-        resolved = super(ConnectionField, self).resolve(instance, args, info)
-        if resolved:
-            resolved = self.wrap_resolved(resolved, instance, args, info)
+        from graphene.relay.types import PageInfo
+        schema = info.schema.graphene_schema
+
+        orig_resolved = super(ConnectionField, self).resolve(instance, args, info)
+        if orig_resolved:
+            resolved = self.wrap_resolved(orig_resolved, instance, args, info)
             assert isinstance(
                 resolved, Iterable), 'Resolved value from the connection field have to be iterable'
-            return connection_from_list(resolved, args)
+
+            node = self.get_object_type(schema)
+            connection_type = self.get_connection_type(node)
+            edge_type = self.get_edge_type(node)
+
+            connection = connection_from_list(resolved, args, connection_type=connection_type,
+                                              edge_type=edge_type, pageinfo_type=PageInfo)
+            connection.set_connection_data(orig_resolved)
+            return connection
+
+    @memoize
+    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)
+
+    @memoize
+    def get_edge_type(self, node):
+        return self.edge_type or node.get_edge_type()
 
     @memoize
     def internal_type(self, schema):
         from graphene.relay.utils import is_node
         node = self.get_object_type(schema)
         assert is_node(node), 'Only nodes have connections.'
         schema.register(node)
-        edge_node_type = self.edge_type.for_node(node)
-        connection_node_type = self.connection_type.for_node(node, edge_type=edge_node_type)
-        return connection_node_type.internal_type(schema)
+
+        return self.get_connection_type(node).internal_type(schema)
 
 
 class NodeField(Field):

graphene/relay/types.py

@@ -1,43 +1,13 @@
 from graphql_relay.node.node import (
     to_global_id
 )
-from graphql_relay.connection.connection import (
-    connection_definitions
-)
 
 from graphene.core.types import Interface, ObjectType
 from graphene.core.fields import BooleanField, StringField, ListField, Field
 from graphene.relay.fields import GlobalIDField
 from graphene.utils import memoize
 
 
-class BaseNode(object):
-    @classmethod
-    @memoize
-    def get_connection(cls, schema):
-        _type = cls.internal_type(schema)
-        type_name = cls._meta.type_name
-        connection = connection_definitions(type_name, _type).connection_type
-        return connection
-
-    @classmethod
-    def _prepare_class(cls):
-        from graphene.relay.utils import is_node
-        if is_node(cls):
-            assert hasattr(
-                cls, 'get_node'), 'get_node classmethod not found in %s Node' % cls
-
-    @classmethod
-    def to_global_id(cls, instance, args, info):
-        type_name = cls._meta.type_name
-        return to_global_id(type_name, instance.id)
-
-
-class Node(BaseNode, Interface):
-    '''An object with an ID'''
-    id = GlobalIDField()
-
-
 class PageInfo(ObjectType):
     has_next_page = BooleanField(required=True, description='When paginating forwards, are there more items?')
     has_previous_page = BooleanField(required=True, description='When paginating backwards, are there more items?')
@@ -47,26 +17,70 @@ class PageInfo(ObjectType):
 
 class Edge(ObjectType):
     '''An edge in a connection.'''
+    class Meta:
+        type_name = 'DefaultEdge'
+
     node = Field(lambda field: field.object_type.node_type, description='The item at the end of the edge')
-    end_cursor = StringField(required=True, description='A cursor for use in pagination')
+    cursor = StringField(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'
-        return type('%sEdge' % node._meta.type_name, (cls, ), {'node_type': node})
+        return type('%s%s' % (node._meta.type_name, cls._meta.type_name), (cls, ), {'node_type': node})
 
 
 class Connection(ObjectType):
     '''A connection to a list of items.'''
+    class Meta:
+        type_name = 'DefaultConnection'
+
     page_info = Field(PageInfo, required=True, description='The Information to aid in pagination')
     edges = ListField(lambda field: field.object_type.edge_type, description='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
         assert is_node(node), 'ObjectTypes in a connection have to be Nodes'
-        return type('%sConnection' % node._meta.type_name, (cls, ), {'edge_type': edge_type.for_node(node)})
+        return type('%s%s' % (node._meta.type_name, cls._meta.type_name), (cls, ), {'edge_type': edge_type.for_node(node)})
+
+    def set_connection_data(self, data):
+        self._connection_data = data
+
+    def get_connection_data(self):
+        return self._connection_data
+
+
+class BaseNode(object):
+    @classmethod
+    def _prepare_class(cls):
+        from graphene.relay.utils import is_node
+        if is_node(cls):
+            assert hasattr(
+                cls, 'get_node'), 'get_node classmethod not found in %s Node' % cls
+
+    @classmethod
+    def to_global_id(cls, instance, args, info):
+        type_name = cls._meta.type_name
+        return to_global_id(type_name, instance.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 Node(BaseNode, Interface):
+    '''An object with an ID'''
+    id = GlobalIDField()

setup.py

@@ -57,7 +57,7 @@ def run_tests(self):
         'six>=1.10.0',
         'blinker',
         'graphql-core==0.4.7b0',
-        'graphql-relay==0.2.0'
+        'graphql-relay==0.3.3'
     ],
     tests_require=[
         'pytest>=2.7.2',

tests/relay/test_relay.py

@@ -24,8 +24,8 @@ class Part(relay.Node):
 
 def test_node_should_have_same_connection_always():
     s = object()
-    connection1 = OtherNode.get_connection(s)
-    connection2 = OtherNode.get_connection(s)
+    connection1 = relay.Connection.for_node(OtherNode)
+    connection2 = relay.Connection.for_node(OtherNode)
 
     assert connection1 == connection2
 

tox.ini

@@ -7,7 +7,7 @@ deps=
     django>=1.8.0,<1.9
     pytest-django
     graphql-core==0.4.7b0
-    graphql-relay==0.2.0
+    graphql-relay==0.3.3
     six
     blinker
     singledispatch