graphene/UPGRADE-v2.0.md

v2.0 Upgrade Guide

ObjectType, Interface, InputObjectType, Scalar and Enum implementations have been quite simplified, without the need to define a explicit Metaclass for each subtype.

It also improves the field resolvers, simplifying the code the developer has to write to use them.

Deprecations:

• AbstractType
• resolve_only_args
• Mutation.Input

Breaking changes:

• Simpler Resolvers
• Node Connections

New Features!

• InputObjectType
• Meta as Class arguments (only available for Python 3)

The type metaclasses are now deleted as they are no longer necessary. If your code was depending on this strategy for creating custom attrs, see an example on how to do it in 2.0.

Deprecations

AbstractType deprecated

AbstractType is deprecated in graphene 2.0, you can now use normal inheritance instead.

Before:

class CommonFields(AbstractType):
    name = String()

class Pet(CommonFields, Interface):
    pass

With 2.0:

class CommonFields(object):
    name = String()

class Pet(CommonFields, Interface):
    pass

resolve_only_args

resolve_only_args is now deprecated as the resolver API has been simplified.

Before:

class User(ObjectType):
    name = String()

    @resolve_only_args
    def resolve_name(self):
        return self.name

With 2.0:

class User(ObjectType):
    name = String()

    def resolve_name(self, info):
        return self.name

Mutation.Input

Mutation.Input is now deprecated in favor of using Mutation.Arguments (ClientIDMutation still uses Input).

Before:

class User(Mutation):
    class Input:
        name = String()

With 2.0:

class User(Mutation):
    class Arguments:
        name = String()

Breaking Changes

Simpler resolvers

All the resolvers in graphene have been simplified. Prior to Graphene 2.0, all resolvers required four arguments: (root, args, context, info). Now, resolver args are passed as keyword arguments to the function, and context argument dissapeared in favor of info.context.

Before:

my_field = graphene.String(my_arg=graphene.String())

def resolve_my_field(self, args, context, info):
    my_arg = args.get('my_arg')
    return ...

With 2.0:

my_field = graphene.String(my_arg=graphene.String())

def resolve_my_field(self, info, my_arg):
    return ...

PS.: Take care with receiving args like my_arg as above. This doesn't work for optional (non-required) arguments as stantard Connection's arguments (first, before, after, before). You may need something like this:

def resolve_my_field(self, info, known_field1, known_field2, **args): ## get other args with: args.get('arg_key')

And, if you need the context in the resolver, you can use info.context:

my_field = graphene.String(my_arg=graphene.String())

def resolve_my_field(self, info, my_arg):
    context = info.context
    return ...

Node Connections

Node types no longer have a Connection by default. In 2.0 and onwards Connections should be defined explicitly.

Before:

class User(ObjectType):
    class Meta:
        interfaces = [relay.Node]
    name = String()

class Query(ObjectType):
    user_connection = relay.ConnectionField(User)

With 2.0:

class User(ObjectType):
    class Meta:
        interfaces = [relay.Node]
    name = String()

class UserConnection(relay.Connection):
    class Meta:
        node = User

class Query(ObjectType):
    user_connection = relay.ConnectionField(UserConnection)

Node.get_node

The method get_node in ObjectTypes that have Node as interface, changes its API. From def get_node(cls, id, context, info) to def get_node(cls, info, id).

class MyObject(ObjectType):
    class Meta:
        interfaces = (Node, )

    @classmethod
    def get_node(cls, id, context, info):
        return ...

To:

class MyObject(ObjectType):
    class Meta:
        interfaces = (Node, )

    @classmethod
    def get_node(cls, info, id):
        return ...

Mutation.mutate

Now only receives (self, info, **args) and is not a @classmethod

Before:

class SomeMutation(Mutation):
    ...

    @classmethod
    def mutate(cls, instance, args, context, info):
        ...

With 2.0:

class SomeMutation(Mutation):
    ...

    def mutate(self, info, **args):
        ...

With 2.0 you can also get your declared (as above) args this way:

class SomeMutation(Mutation):
    class Arguments:
        first_name = String(required=True)
        last_name = String(required=True)
    ...

    def mutate(self, info, first_name, last_name):
        ...

ClientIDMutation.mutate_and_get_payload

Now only receives (root, info, **input)

Middlewares

If you are using Middelwares, you need to some adjustments:

Before:

class MyGrapheneMiddleware(object):  
    def resolve(self, next_mw, root, args, context, info):

        ## Middleware code

        return next_mw(root, args, context, info)

With 2.0:

class MyGrapheneMiddleware(object):  
    def resolve(self, next_mw, root, info, **args):
        context = info.context

        ## Middleware code

        info.context = context
        return next_mw(root, info, **args)```

New Features

InputObjectType

If you are using InputObjectType, you now can access its fields via getattr (my_input.myattr) when resolving, instead of the classic way my_input['myattr'].

And also use custom defined properties on your input class.

Example. Before:

class UserInput(InputObjectType):
    id = ID(required=True)

def is_valid_input(input):
    return input.get('id').startswith('userid_')

class Query(ObjectType):
    user = graphene.Field(User, input=UserInput())

    @resolve_only_args
    def resolve_user(self, input):
        user_id = input.get('id')
        if is_valid_input(user_id):
            return get_user(user_id)

With 2.0:

class UserInput(InputObjectType):
    id = ID(required=True)

    @property
    def is_valid(self):
        return self.id.startswith('userid_')

class Query(ObjectType):
    user = graphene.Field(User, input=UserInput())

    def resolve_user(self, info, input):
        if input.is_valid:
            return get_user(input.id)

Meta as Class arguments

Now you can use the meta options as class arguments (ONLY PYTHON 3).

Before:

class Dog(ObjectType):
    class Meta:
        interfaces = [Pet]
    name = String()

With 2.0:

class Dog(ObjectType, interfaces=[Pet]):
    name = String()

Abstract types

Now you can create abstact types super easily, without the need of subclassing the meta.

class Base(ObjectType):
    class Meta:
        abstract = True

    id = ID()

    def resolve_id(self, info):
        return "{type}_{id}".format(
            type=self.__class__.__name__,
            id=self.id
        )

UUID Scalar

In Graphene 2.0 there is a new dedicated scalar for UUIDs, UUID.