Node

use Resolver to define a relay node.

validate method is required to determinate value type when using graphql interface or union.

example:

class Pet(resolver.Resolver):
    schema = {
        'type': {
            'name': models.Pet._meta.get_field('name'),
            'age': models.Pet._meta.get_field('age'),
        },
        'interfaces': (graphene.Node,)
    }

    def get_node(self, id_):
        return models.Pet.objects.get(pk=id_)

    def validate(self, value):
        return isinstance(value, models.Pet)

class Query(graphene.ObjectType):
    node = graphene.Node.Field()

schema = graphene.Schema(query=Query, types=[Pet.as_type()])