Django（74）drf-spectacular自动生成接口文档

介绍

drf-spectacular是为Django REST Framework生成合理灵活的OpenAPI 3.0模式。它可以自动帮我们提取接口中的信息，从而形成接口文档，而且内容十分详细，再也不用为写接口文档而心烦了

这个库主要实现了3个目标

• 从DRF中提取更多的schema信息
• 提供灵活性，使schema在现实世界中可用(不仅仅是示例)
• 生成一个与最流行的客户端生成器配合良好的schema

环境准备

• Python >= 3.6
• Django (2.2, 3.1, 3.2)
• Django REST Framework (3.10, 3.11, 3.12)

安装

使用pip命令安装

pip install drf-spectacular

然后在settings.py的INSTALLED_APPS安装drf-spectacular

INSTALLED_APPS = [
    # ALL YOUR APPS
    'drf_spectacular',
]

最后向DRF注册我们壮观的AutoSchema

REST_FRAMEWORK = {
    # YOUR SETTINGS
    'DEFAULT_SCHEMA_CLASS': 'drf_spectacular.openapi.AutoSchema',
}

drf-spectacular有健全的默认设置，非常好用开箱即用，不需要指定任何设置，但我们建议至少指定一些元数据

SPECTACULAR_SETTINGS = {
    'TITLE': 'API接口文档',
    'DESCRIPTION': '项目详情介绍',
    'VERSION': '1.0.0',
    # OTHER SETTINGS
}

使用方式

我们只需要在urls.py中添加接口地址即可

from drf_spectacular.views import SpectacularAPIView, SpectacularRedocView, SpectacularSwaggerView
urlpatterns = [
    # YOUR PATTERNS
    path('api/schema/', SpectacularAPIView.as_view(), name='schema'),
    # Optional UI:
    path('api/schema/swagger-ui/', SpectacularSwaggerView.as_view(url_name='schema'), name='swagger-ui'),  # swagger接口文档
    path('api/schema/redoc/', SpectacularRedocView.as_view(url_name='schema'), name='redoc'),  # redoc接口文档
]

然后我们启动项目，访问http://127.0.0.1:8000/api/schema/swagger-ui/，就会出现接口文档



我们可以看到图上有我们之前在settings.py中配置的TITLE和DESCRIPTION和VERSION，如果想自定义更多的设置，请看文档

自定义接口内容信息

上面我们可以访问swagger接口文档，但是我们点开接口会发现没有任何内容信息



所以我们还需要在view视图中，使用装饰器@extend_schema来制定接口文档中的接口信息

我们先来看下装饰器extend_schema的源码

def extend_schema(
        operation_id: Optional[str] = None,
        parameters: Optional[List[Union[OpenApiParameter, _SerializerType]]] = None,
        request: Any = empty,
        responses: Any = empty,
        auth: Optional[List[str]] = None,
        description: Optional[str] = None,
        summary: Optional[str] = None,
        deprecated: Optional[bool] = None,
        tags: Optional[List[str]] = None,
        exclude: bool = False,
        operation: Optional[Dict] = None,
        methods: Optional[List[str]] = None,
        versions: Optional[List[str]] = None,
        examples: Optional[List[OpenApiExample]] = None,
        extensions: Optional[Dict[str, Any]] = None,
) -> Callable[[F], F]:
    """
    Decorator mainly for the "view" method kind. Partially or completely overrides
    what would be otherwise generated by drf-spectacular.

    :param operation_id: replaces the auto-generated operation_id. make sure there
        are no naming collisions.
    :param parameters: list of additional or replacement parameters added to the
        auto-discovered fields.
    :param responses: replaces the discovered Serializer. Takes a variety of
        inputs that can be used individually or combined

        - ``Serializer`` class
        - ``Serializer`` instance (e.g. ``Serializer(many=True)`` for listings)
        - basic types or instances of ``OpenApiTypes``
        - :class:`.OpenApiResponse` for bundling any of the other choices together with
          either a dedicated response description and/or examples.
        - :class:`.PolymorphicProxySerializer` for signaling that
          the operation may yield data from different serializers depending
          on the circumstances.
        - ``dict`` with status codes as keys and one of the above as values.
          Additionally in this case, it is also possible to provide a raw schema dict
          as value.
        - ``dict`` with tuples (status_code, media_type) as keys and one of the above
          as values. Additionally in this case, it is also possible to provide a raw
          schema dict as value.
    :param request: replaces the discovered ``Serializer``. Takes a variety of inputs

        - ``Serializer`` class/instance
        - basic types or instances of ``OpenApiTypes``
        - :class:`.PolymorphicProxySerializer` for signaling that the operation
          accepts a set of different types of objects.
        - ``dict`` with media_type as keys and one of the above as values. Additionally in
          this case, it is also possible to provide a raw schema dict as value.
    :param auth: replace discovered auth with explicit list of auth methods
    :param description: replaces discovered doc strings
    :param summary: an optional short summary of the description
    :param deprecated: mark operation as deprecated
    :param tags: override default list of tags
    :param exclude: set True to exclude operation from schema
    :param operation: manually override what auto-discovery would generate. you must
        provide a OpenAPI3-compliant dictionary that gets directly translated to YAML.
    :param methods: scope extend_schema to specific methods. matches all by default.
    :param versions: scope extend_schema to specific API version. matches all by default.
    :param examples: attach request/response examples to the operation
    :param extensions: specification extensions, e.g. ``x-badges``, ``x-code-samples``, etc.
    :return:
    """
    if methods is not None:
        methods = [method.upper() for method in methods]

    def decorator(f):
        BaseSchema = (
            # explicit manually set schema or previous view annotation
            getattr(f, 'schema', None)
            # previously set schema with @extend_schema on views methods
            or getattr(f, 'kwargs', {}).get('schema', None)
            # previously set schema with @extend_schema on @api_view
            or getattr(getattr(f, 'cls', None), 'kwargs', {}).get('schema', None)
            # the default
            or api_settings.DEFAULT_SCHEMA_CLASS
        )

        if not inspect.isclass(BaseSchema):
            BaseSchema = BaseSchema.__class__

        def is_in_scope(ext_schema):
            version, _ = ext_schema.view.determine_version(
                ext_schema.view.request,
                **ext_schema.view.kwargs
            )
            version_scope = versions is None or version in versions
            method_scope = methods is None or ext_schema.method in methods
            return method_scope and version_scope

        class ExtendedSchema(BaseSchema):
            def get_operation(self, path, path_regex, path_prefix, method, registry):
                self.method = method.upper()

                if exclude and is_in_scope(self):
                    return None
                if operation is not None and is_in_scope(self):
                    return operation
                return super().get_operation(path, path_regex, path_prefix, method, registry)

            def get_operation_id(self):
                if operation_id and is_in_scope(self):
                    return operation_id
                return super().get_operation_id()

            def get_override_parameters(self):
                if parameters and is_in_scope(self):
                    return super().get_override_parameters() + parameters
                return super().get_override_parameters()

            def get_auth(self):
                if auth and is_in_scope(self):
                    return auth
                return super().get_auth()

            def get_examples(self):
                if examples and is_in_scope(self):
                    return super().get_examples() + examples
                return super().get_examples()

            def get_request_serializer(self):
                if request is not empty and is_in_scope(self):
                    return request
                return super().get_request_serializer()

            def get_response_serializers(self):
                if responses is not empty and is_in_scope(self):
                    return responses
                return super().get_response_serializers()

            def get_description(self):
                if description and is_in_scope(self):
                    return description
                return super().get_description()

            def get_summary(self):
                if summary and is_in_scope(self):
                    return str(summary)
                return super().get_summary()

            def is_deprecated(self):
                if deprecated and is_in_scope(self):
                    return deprecated
                return super().is_deprecated()

            def get_tags(self):
                if tags is not None and is_in_scope(self):
                    return tags
                return super().get_tags()

            def get_extensions(self):
                if extensions and is_in_scope(self):
                    return extensions
                return super().get_extensions()

        if inspect.isclass(f):
            # either direct decoration of views, or unpacked @api_view from OpenApiViewExtension
            if operation_id is not None or operation is not None:
                error(
                    f'using @extend_schema on viewset class {f.__name__} with parameters '
                    f'operation_id or operation will most likely result in a broken schema.'
                )
            # reorder schema class MRO so that view method annotation takes precedence
            # over view class annotation. only relevant if there is a method annotation
            for view_method_name in get_view_method_names(view=f, schema=BaseSchema):
                if 'schema' not in getattr(getattr(f, view_method_name), 'kwargs', {}):
                    continue
                view_method = isolate_view_method(f, view_method_name)
                view_method.kwargs['schema'] = type(
                    'ExtendedMetaSchema', (view_method.kwargs['schema'], ExtendedSchema), {}
                )
            # persist schema on class to provide annotation to derived view methods.
            # the second purpose is to serve as base for view multi-annotation
            f.schema = ExtendedSchema()
            return f
        elif callable(f) and hasattr(f, 'cls'):
            # 'cls' attr signals that as_view() was called, which only applies to @api_view.
            # keep a "unused" schema reference at root level for multi annotation convenience.
            setattr(f.cls, 'kwargs', {'schema': ExtendedSchema})
            # set schema on method kwargs context to emulate regular view behaviour.
            for method in f.cls.http_method_names:
                setattr(getattr(f.cls, method), 'kwargs', {'schema': ExtendedSchema})
            return f
        elif callable(f):
            # custom actions have kwargs in their context, others don't. create it so our create_view
            # implementation can overwrite the default schema
            if not hasattr(f, 'kwargs'):
                f.kwargs = {}
            # this simulates what @action is actually doing. somewhere along the line in this process
            # the schema is picked up from kwargs and used. it's involved my dear friends.
            # use class instead of instance due to descriptor weakref reverse collisions
            f.kwargs['schema'] = ExtendedSchema
            return f
        else:
            return f

    return decorator

这个装饰器主要用于view，通过drf-spectacular部分或完全的覆盖去产生些东西

先来看下几个初始化参数

• operation_id：一个唯一标识ID，基本用不到
• parameters：添加到列表中的附加或替换参数去自动发现字段。
• responses：替换Serializer。需要各种各样的可单独使用或组合使用的输入(有以下7种)
  • Serializer类
  • 序列化实例，比如：Serializer(many=True)
  • OpenApiTypes的基本类型或者实例
  • OpenApiResponse类
  • PolymorphicProxySerializer类
  • 1个字典，以状态码作为键， 以上其中一项作为值(是最常用的，格式{200, None})
  • 1个字典，以状态码作为键，以media_type作为值
• request：替换序列化，接受各种输入
  • Serializer 类或者实例
  • OpenApiTypes基本类型或者实例
  • PolymorphicProxySerializer类
  • 1个字典，以media_type作为键，以上其中一项作为值
• auth：用auth方法的显式列表替换发现的auth
• description：替换发现的文档字符串
• summary：一个可选的短的总结描述
• deprecated：将操作标记为已弃用
• tags：覆盖默认标记列表
• exclude：设置为True以从schema中排除操作
• operation：手动覆盖自动发现将生成的内容。你必须提供一个兼容OpenAPI3的字典，该字典可以直接翻译成YAML。
• methods：检查extend_schema中特殊的方法，默认匹配所有
• versions：检查extend_schema中特殊的API版本，默认匹配所有
• example：将请求/响应示例附加到操作中
• extensions：规范扩展