Source code for graphene.types.argument

from itertools import chain
from graphql import Undefined

from .dynamic import Dynamic
from .mountedtype import MountedType
from .structures import NonNull
from .utils import get_type


[docs]class Argument(MountedType):
    """
    Makes an Argument available on a Field in the GraphQL schema.

    Arguments will be parsed and provided to resolver methods for fields as keyword arguments.

    All ``arg`` and ``**extra_args`` for a ``graphene.Field`` are implicitly mounted as Argument
    using the below parameters.

    .. code:: python

        from graphene import String, Boolean, Argument

        age = String(
            # Boolean implicitly mounted as Argument
            dog_years=Boolean(description="convert to dog years"),
            # Boolean explicitly mounted as Argument
            decades=Argument(Boolean, default_value=False),
        )

    args:
        type (class for a graphene.UnmountedType): must be a class (not an instance) of an
            unmounted graphene type (ex. scalar or object) which is used for the type of this
            argument in the GraphQL schema.
        required (optional, bool): indicates this argument as not null in the graphql schema. Same behavior
            as graphene.NonNull. Default False.
        name (optional, str): the name of the GraphQL argument. Defaults to parameter name.
        description (optional, str): the description of the GraphQL argument in the schema.
        default_value (optional, Any): The value to be provided if the user does not set this argument in
            the operation.
        deprecation_reason (optional, str): Setting this value indicates that the argument is
            depreciated and may provide instruction or reason on how for clients to proceed. Cannot be
            set if the argument is required (see spec).
    """

    def __init__(
        self,
        type_,
        default_value=Undefined,
        deprecation_reason=None,
        description=None,
        name=None,
        required=False,
        _creation_counter=None,
    ):
        super(Argument, self).__init__(_creation_counter=_creation_counter)

        if required:
            assert (
                deprecation_reason is None
            ), f"Argument {name} is required, cannot deprecate it."
            type_ = NonNull(type_)

        self.name = name
        self._type = type_
        self.default_value = default_value
        self.description = description
        self.deprecation_reason = deprecation_reason

    @property
    def type(self):
        return get_type(self._type)

    def __eq__(self, other):
        return isinstance(other, Argument) and (
            self.name == other.name
            and self.type == other.type
            and self.default_value == other.default_value
            and self.description == other.description
            and self.deprecation_reason == other.deprecation_reason
        )


def to_arguments(args, extra_args=None):
    from .unmountedtype import UnmountedType
    from .field import Field
    from .inputfield import InputField

    if extra_args:
        extra_args = sorted(extra_args.items(), key=lambda f: f[1])
    else:
        extra_args = []
    iter_arguments = chain(args.items(), extra_args)
    arguments = {}
    for default_name, arg in iter_arguments:
        if isinstance(arg, Dynamic):
            arg = arg.get_type()
            if arg is None:
                # If the Dynamic type returned None
                # then we skip the Argument
                continue

        if isinstance(arg, UnmountedType):
            arg = Argument.mounted(arg)

        if isinstance(arg, (InputField, Field)):
            raise ValueError(
                f"Expected {default_name} to be Argument, "
                f"but received {type(arg).__name__}. Try using Argument({arg.type})."
            )

        if not isinstance(arg, Argument):
            raise ValueError(f'Unknown argument "{default_name}".')

        arg_name = default_name or arg.name
        assert (
            arg_name not in arguments
        ), f'More than one Argument have same name "{arg_name}".'
        arguments[arg_name] = arg

    return arguments