Source code for graphene.types.objecttype

from .base import BaseOptions, BaseType, BaseTypeMeta
from .field import Field
from .interface import Interface
from .utils import yank_fields_from_attrs

try:
    from dataclasses import make_dataclass, field
except ImportError:
    from ..pyutils.dataclasses import make_dataclass, field  # type: ignore

# For static type checking with Mypy
MYPY = False
if MYPY:
    from typing import Dict, Iterable, Type  # NOQA


class ObjectTypeOptions(BaseOptions):
    fields = None  # type: Dict[str, Field]
    interfaces = ()  # type: Iterable[Type[Interface]]


class ObjectTypeMeta(BaseTypeMeta):
    def __new__(cls, name_, bases, namespace, **options):
        # Note: it's safe to pass options as keyword arguments as they are still type-checked by ObjectTypeOptions.

        # We create this type, to then overload it with the dataclass attrs
        class InterObjectType:
            pass

        base_cls = super().__new__(
            cls, name_, (InterObjectType,) + bases, namespace, **options,
        )
        if base_cls._meta:
            fields = [
                (
                    key,
                    "typing.Any",
                    field(
                        default=field_value.default_value
                        if isinstance(field_value, Field)
                        else None
                    ),
                )
                for key, field_value in base_cls._meta.fields.items()
            ]
            dataclass = make_dataclass(name_, fields, bases=())
            InterObjectType.__init__ = dataclass.__init__
            InterObjectType.__eq__ = dataclass.__eq__
            InterObjectType.__repr__ = dataclass.__repr__
        return base_cls


[docs]class ObjectType(BaseType, metaclass=ObjectTypeMeta): """ Object Type Definition Almost all of the GraphQL types you define will be object types. Object types have a name, but most importantly describe their fields. The name of the type defined by an _ObjectType_ defaults to the class name. The type description defaults to the class docstring. This can be overridden by adding attributes to a Meta inner class. The class attributes of an _ObjectType_ are mounted as instances of ``graphene.Field``. Methods starting with ``resolve_<field_name>`` are bound as resolvers of the matching Field name. If no resolver is provided, the default resolver is used. Ambiguous types with Interface and Union can be determined through``is_type_of`` method and ``Meta.possible_types`` attribute. .. code:: python from graphene import ObjectType, String, Field class Person(ObjectType): class Meta: description = 'A human' # implicitly mounted as Field first_name = String() # explicitly mounted as Field last_name = Field(String) def resolve_last_name(parent, info): return last_name ObjectType must be mounted using ``graphene.Field``. .. code:: python from graphene import ObjectType, Field class Query(ObjectType): person = Field(Person, description="My favorite person") Meta class options (optional): name (str): Name of the GraphQL type (must be unique in schema). Defaults to class name. description (str): Description of the GraphQL type in the schema. Defaults to class docstring. interfaces (Iterable[graphene.Interface]): GraphQL interfaces to extend with this object. all fields from interface will be included in this object's schema. possible_types (Iterable[class]): Used to test parent value object via isinstance to see if this type can be used to resolve an ambiguous type (interface, union). default_resolver (any Callable resolver): Override the default resolver for this type. Defaults to graphene default resolver which returns an attribute or dictionary key with the same name as the field. fields (Dict[str, graphene.Field]): Dictionary of field name to Field. Not recommended to use (prefer class attributes). An _ObjectType_ can be used as a simple value object by creating an instance of the class. .. code:: python p = Person(first_name='Bob', last_name='Roberts') assert p.first_name == 'Bob' Args: *args (List[Any]): Positional values to use for Field values of value object **kwargs (Dict[str: Any]): Keyword arguments to use for Field values of value object """ @classmethod def __init_subclass_with_meta__( cls, interfaces=(), possible_types=(), default_resolver=None, _meta=None, **options, ): if not _meta: _meta = ObjectTypeOptions(cls) fields = {} for interface in interfaces: assert issubclass( interface, Interface ), f'All interfaces of {cls.__name__} must be a subclass of Interface. Received "{interface}".' fields.update(interface._meta.fields) for base in reversed(cls.__mro__): fields.update(yank_fields_from_attrs(base.__dict__, _as=Field)) assert not (possible_types and cls.is_type_of), ( f"{cls.__name__}.Meta.possible_types will cause type collision with {cls.__name__}.is_type_of. " "Please use one or other." ) if _meta.fields: _meta.fields.update(fields) else: _meta.fields = fields if not _meta.interfaces: _meta.interfaces = interfaces _meta.possible_types = possible_types _meta.default_resolver = default_resolver super(ObjectType, cls).__init_subclass_with_meta__(_meta=_meta, **options) is_type_of = None