DRF源码解析4--版本控制组件的封装

DRF

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 2020/02/22   Share

一.DRF中APIView的initial()方法初始化版本信息

在讲到DRF对ruquest的封装时,返回新封装的Request后,DRF执行了initial()方法对组件的初始化

def initial(self, request, *args, **kwargs):
	# 版本控制组件
       version, scheme = self.determine_version(request, *args, **kwargs)
	# 将版本空值信息写入request中
       request.version, request.versioning_scheme = version, scheme

       # Ensure that the incoming request is permitted
       # 认证组件
       self.perform_authentication(request)
       # 权限组件
       self.check_permissions(request)
       # 频率
       self.check_throttles(request)

1.1重写determine_version()自定制版本信息

  def determine_version(self, request, *args, **kwargs):
      """
      If versioning is being used, then determine any API version for the
      incoming request. Returns a two-tuple of (version, versioning_scheme)
      """
      if self.versioning_class is None:
          return (None, None)
# self.versioning_class是drf配置默认的类,说明我们自定义版本时要重写这个方法
      scheme = self.versioning_class()
      return (scheme.determine_version(request, *args, **kwargs), scheme)

二.rest_framework.versioning提供的版本控制方法

versioning

2.1 BaseVersioning

class BaseVersioning:
	# default_version(None), allowed_versions(None), version_param可以在settings中重新配置
    default_version = api_settings.DEFAULT_VERSION
    allowed_versions = api_settings.ALLOWED_VERSIONS
    version_param = api_settings.VERSION_PARAM

    def determine_version(self, request, *args, **kwargs):
		# 在继承该类时要重写determine_version(方法)
        msg = '{cls}.determine_version() must be implemented.'
        raise NotImplementedError(msg.format(
            cls=self.__class__.__name__
        ))

    def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
		# 和django.urls.reverse大致相同,
		# 但可以选择接受一个请求并返回使用请求获取基本URL的标准URL。
        return _reverse(viewname, args, kwargs, request, format, **extra)

    def is_allowed_version(self, version):
        if not self.allowed_versions:
            return True
        return ((version is not None and version == self.default_version) or
                (version in self.allowed_versions))

2.2 URLPathVersioning

class URLPathVersioning(BaseVersioning):
    """
    To the client this is the same style as `NamespaceVersioning`.
    The difference is in the backend - this implementation uses
    Django's URL keyword arguments to determine the version.

    An example URL conf for two views that accept two different versions.
    可以看到版本信息就在url中
    urlpatterns = [
        url(r'^(?P<version>[v1|v2]+)/users/$', users_list, name='users-list'),
        url(r'^(?P<version>[v1|v2]+)/users/(?P<pk>[0-9]+)/$', users_detail, name='users-detail')
    ]

    GET /1.0/something/ HTTP/1.1
    Host: example.com
    Accept: application/json
    """
    invalid_version_message = _('Invalid version in URL path.')

    def determine_version(self, request, *args, **kwargs):
	 # self.version_param,self.default_version是父类中的属性,可以自定义
        version = kwargs.get(self.version_param, self.default_version)
        if version is None:
			# 如果没有自己配置默认为DRF默认的版本信息
            version = self.default_version

        if not self.is_allowed_version(version):
            raise exceptions.NotFound(self.invalid_version_message)
        return version

    def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
        if request.version is not None:
            kwargs = {} if (kwargs is None) else kwargs
			# self.version_param就是版本的key
            kwargs[self.version_param] = request.version

        return super().reverse(
            viewname, args, kwargs, request, format, **extra

其他的类基本配置都差不多

Author：liangweijiang

原文链接：https://liangweijiang.github.io/2020/02/22/DRF-04/

发表日期：February 22nd 2020, 10:09:24 pm

更新日期：February 22nd 2020, 10:11:09 pm

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CATALOG

1. 一.DRF中APIView的initial()方法初始化版本信息
1. 1.1. 1.1重写determine_version()自定制版本信息
2. 二.rest_framework.versioning提供的版本控制方法
1. 2.1. 2.1 BaseVersioning
2. 2.2. 2.2 URLPathVersioning

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