Source code for apispec.ext.marshmallow

"""marshmallow plugin for apispec. Allows passing a marshmallow
`Schema` to `spec.components.schema <apispec.core.Components.schema>`,
`spec.components.parameter <apispec.core.Components.parameter>`,
`spec.components.response <apispec.core.Components.response>`
(for response and headers schemas) and
`spec.path <apispec.APISpec.path>` (for responses and response headers).

Requires marshmallow>=3.13.0.

``MarshmallowPlugin`` maps marshmallow ``Field`` classes with OpenAPI types and

It inspects field attributes to automatically document properties
such as read/write-only, range and length constraints, etc.

OpenAPI properties can also be passed as metadata to the ``Field`` instance
if they can't be inferred from the field attributes (`description`,...), or to
override automatic documentation (`readOnly`,...). A metadata attribute is used
in the documentation either if it is a valid OpenAPI property, or if it starts
with `"x-"` (vendor extension).

.. warning::

    ``MarshmallowPlugin`` infers the ``default`` property from the
    ``load_default`` attribute of the ``Field`` (unless ``load_default`` is a
    callable). Since default values are entered in deserialized form,
    the value displayed in the doc is serialized by the ``Field`` instance.
    This may lead to inaccurate documentation in very specific cases.
    The default value to display in the documentation can be
    specified explicitly by passing ``default`` as field metadata.


    from pprint import pprint
    import datetime as dt

    from apispec import APISpec
    from apispec.ext.marshmallow import MarshmallowPlugin
    from marshmallow import Schema, fields

    spec = APISpec(
        title="Example App",

    class UserSchema(Schema):
        id = fields.Int(dump_only=True)
        name = fields.Str(metadata={"description": "The user's name"})
        created = fields.DateTime(
            metadata={"default": "The current datetime"}

    spec.components.schema("User", schema=UserSchema)
    # {'User': {'properties': {'created': {'default': 'The current datetime',
    #                                      'format': 'date-time',
    #                                      'readOnly': True,
    #                                      'type': 'string'},
    #                          'id': {'readOnly': True,
    #                                 'type': 'integer'},
    #                          'name': {'description': "The user's name",
    #                                   'type': 'string'}},
    #           'type': 'object'}}

# pyright: reportIncompatibleMethodOverride=false
from __future__ import annotations

import typing
import warnings

from marshmallow import Schema
from packaging.version import Version

from apispec import APISpec, BasePlugin

from .common import make_schema_key, resolve_schema_cls, resolve_schema_instance
from .openapi import OpenAPIConverter
from .schema_resolver import SchemaResolver

[docs] def resolver(schema: type[Schema]) -> str: """Default schema name resolver function that strips 'Schema' from the end of the class name.""" resolved = resolve_schema_cls(schema) schema_cls = resolved[0] if isinstance(resolved, list) else resolved name = schema_cls.__name__ if name.endswith("Schema"): name = name[:-6] or name return name.strip()
[docs] class MarshmallowPlugin(BasePlugin): """APISpec plugin for translating marshmallow schemas to OpenAPI/JSONSchema format. :param callable schema_name_resolver: Callable to generate the schema definition name. Receives the `Schema` class and returns the name to be used in refs within the generated spec. When working with circular referencing this function must must not return `None` for schemas in a circular reference chain. Example: :: from apispec.ext.marshmallow.common import resolve_schema_cls def schema_name_resolver(schema): schema_cls = resolve_schema_cls(schema) return schema_cls.__name__ """ Converter = OpenAPIConverter Resolver = SchemaResolver def __init__( self, schema_name_resolver: typing.Callable[[type[Schema]], str] | None = None, ) -> None: super().__init__() self.schema_name_resolver = schema_name_resolver or resolver self.spec: APISpec | None = None self.openapi_version: Version | None = None self.converter: OpenAPIConverter | None = None self.resolver: SchemaResolver | None = None
[docs] def init_spec(self, spec: APISpec) -> None: super().init_spec(spec) self.spec = spec self.openapi_version = spec.openapi_version self.converter = self.Converter( openapi_version=spec.openapi_version, schema_name_resolver=self.schema_name_resolver, spec=spec, ) self.resolver = self.Resolver( openapi_version=spec.openapi_version, converter=self.converter )
[docs] def map_to_openapi_type(self, field_cls, *args): """Set mapping for custom field class. :param type field_cls: Field class to set mapping for. ``*args`` can be: - a pair of the form ``(type, format)`` - a core marshmallow field type (in which case we reuse that type's mapping) Examples: :: # Override Integer mapping class Int32(Integer): # ... ma_plugin.map_to_openapi_type(Int32, 'string', 'int32') # Map to ('integer', None) like Integer class IntegerLike(Integer): # ... ma_plugin.map_to_openapi_type(IntegerLike, Integer) """ assert self.converter is not None, "init_spec has not yet been called" return self.converter.map_to_openapi_type(field_cls, *args)
[docs] def schema_helper(self, name, _, schema=None, **kwargs): """Definition helper that allows using a marshmallow :class:`Schema <marshmallow.Schema>` to provide OpenAPI metadata. :param type|Schema schema: A marshmallow Schema class or instance. """ if schema is None: return None schema_instance = resolve_schema_instance(schema) schema_key = make_schema_key(schema_instance) self.warn_if_schema_already_in_spec(schema_key) assert self.converter is not None, "init_spec has not yet been called" self.converter.refs[schema_key] = name json_schema = self.converter.schema2jsonschema(schema_instance) return json_schema
[docs] def parameter_helper(self, parameter, **kwargs): """Parameter component helper that allows using a marshmallow :class:`Schema <marshmallow.Schema>` in parameter definition. :param dict parameter: parameter fields. May contain a marshmallow Schema class or instance. """ assert self.resolver is not None, "init_spec has not yet been called" self.resolver.resolve_schema(parameter) return parameter
[docs] def response_helper(self, response, **kwargs): """Response component helper that allows using a marshmallow :class:`Schema <marshmallow.Schema>` in response definition. :param dict parameter: response fields. May contain a marshmallow Schema class or instance. """ assert self.resolver is not None, "init_spec has not yet been called" self.resolver.resolve_response(response) return response
[docs] def header_helper(self, header: dict, **kwargs: typing.Any): """Header component helper that allows using a marshmallow :class:`Schema <marshmallow.Schema>` in header definition. :param dict header: header fields. May contain a marshmallow Schema class or instance. """ assert self.resolver # needed for mypy self.resolver.resolve_schema(header) return header
[docs] def operation_helper( self, path: str | None = None, operations: dict | None = None, **kwargs: typing.Any, ) -> None: assert self.resolver # needed for mypy self.resolver.resolve_operations(operations)
[docs] def warn_if_schema_already_in_spec(self, schema_key: tuple) -> None: """Method to warn the user if the schema has already been added to the spec. """ assert self.converter # needed for mypy if schema_key in self.converter.refs: warnings.warn( "{} has already been added to the spec. Adding it twice may " "cause references to not resolve properly.".format(schema_key[0]), UserWarning, stacklevel=2, )