mirror of
https://github.com/graphql-python/graphene.git
synced 2024-11-30 05:23:57 +03:00
5cb7d91aaa
* Revise documentation - Add missing reference to `flask-graphql` in integrations - align documentation for resolver arguments (use root for 1st argument instead of self) - explore use of `parent` instead of `root` for first argument - clarify resolvers and object type documentation - add documentation for Meta class options for ObjectType - expand quickstart documentation for first time users - streamline order of documentation for first time users (broad -> specific) - document resolver quirks * explict imports from graphene * rename doc refs for resolvers * suggestions typos and graphene import
141 lines
3.5 KiB
ReStructuredText
141 lines
3.5 KiB
ReStructuredText
.. _Scalars:
|
||
|
||
Scalars
|
||
=======
|
||
|
||
All Scalar types accept the following arguments. All are optional:
|
||
|
||
``name``: *string*
|
||
|
||
Override the name of the Field.
|
||
|
||
``description``: *string*
|
||
|
||
A description of the type to show in the GraphiQL browser.
|
||
|
||
``required``: *boolean*
|
||
|
||
If ``True``, the server will enforce a value for this field. See `NonNull <../list-and-nonnull.html#nonnull>`_. Default is ``False``.
|
||
|
||
``deprecation_reason``: *string*
|
||
|
||
Provide a deprecation reason for the Field.
|
||
|
||
``default_value``: *any*
|
||
|
||
Provide a default value for the Field.
|
||
|
||
|
||
|
||
Base scalars
|
||
------------
|
||
|
||
Graphene defines the following base Scalar Types:
|
||
|
||
``graphene.String``
|
||
|
||
Represents textual data, represented as UTF-8
|
||
character sequences. The String type is most often used by GraphQL to
|
||
represent free-form human-readable text.
|
||
|
||
``graphene.Int``
|
||
|
||
Represents non-fractional signed whole numeric
|
||
values. Int is a signed 32‐bit integer per the
|
||
`GraphQL spec <https://facebook.github.io/graphql/June2018/#sec-Int>`_
|
||
|
||
``graphene.Float``
|
||
|
||
Represents signed double-precision fractional
|
||
values as specified by
|
||
`IEEE 754 <http://en.wikipedia.org/wiki/IEEE_floating_point>`_.
|
||
|
||
``graphene.Boolean``
|
||
|
||
Represents `true` or `false`.
|
||
|
||
``graphene.ID``
|
||
|
||
Represents a unique identifier, often used to
|
||
refetch an object or as key for a cache. The ID type appears in a JSON
|
||
response as a String; however, it is not intended to be human-readable.
|
||
When expected as an input type, any string (such as `"4"`) or integer
|
||
(such as `4`) input value will be accepted as an ID.
|
||
|
||
Graphene also provides custom scalars for Dates, Times, and JSON:
|
||
|
||
``graphene.types.datetime.Date``
|
||
|
||
Represents a Date value as specified by `iso8601 <https://en.wikipedia.org/wiki/ISO_8601>`_.
|
||
|
||
``graphene.types.datetime.DateTime``
|
||
|
||
Represents a DateTime value as specified by `iso8601 <https://en.wikipedia.org/wiki/ISO_8601>`_.
|
||
|
||
``graphene.types.datetime.Time``
|
||
|
||
Represents a Time value as specified by `iso8601 <https://en.wikipedia.org/wiki/ISO_8601>`_.
|
||
|
||
``graphene.types.json.JSONString``
|
||
|
||
Represents a JSON string.
|
||
|
||
|
||
Custom scalars
|
||
--------------
|
||
|
||
You can create custom scalars for your schema.
|
||
The following is an example for creating a DateTime scalar:
|
||
|
||
.. code:: python
|
||
|
||
import datetime
|
||
from graphene.types import Scalar
|
||
from graphql.language import ast
|
||
|
||
class DateTime(Scalar):
|
||
'''DateTime Scalar Description'''
|
||
|
||
@staticmethod
|
||
def serialize(dt):
|
||
return dt.isoformat()
|
||
|
||
@staticmethod
|
||
def parse_literal(node):
|
||
if isinstance(node, ast.StringValue):
|
||
return datetime.datetime.strptime(
|
||
node.value, "%Y-%m-%dT%H:%M:%S.%f")
|
||
|
||
@staticmethod
|
||
def parse_value(value):
|
||
return datetime.datetime.strptime(value, "%Y-%m-%dT%H:%M:%S.%f")
|
||
|
||
Mounting Scalars
|
||
----------------
|
||
|
||
Scalars mounted in a ``ObjectType``, ``Interface`` or ``Mutation`` act as
|
||
``Field``\ s.
|
||
|
||
.. code:: python
|
||
|
||
class Person(graphene.ObjectType):
|
||
name = graphene.String()
|
||
|
||
# Is equivalent to:
|
||
class Person(graphene.ObjectType):
|
||
name = graphene.Field(graphene.String)
|
||
|
||
|
||
**Note:** when using the ``Field`` constructor directly, pass the type and
|
||
not an instance.
|
||
|
||
Types mounted in a ``Field`` act as ``Argument``\ s.
|
||
|
||
|
||
.. code:: python
|
||
|
||
graphene.Field(graphene.String, to=graphene.String())
|
||
|
||
# Is equivalent to:
|
||
graphene.Field(graphene.String, to=graphene.Argument(graphene.String))
|