Django Rest Framework 版本控制

前言

通过DRF写的视图类，都会继承APIVIEW，而APIVIEW类继承VIEW，同时其重写了as_view方法【使之cbv能够url传参】

dispatch方法，重新封装了request对象

将老的request对象赋值为_request

前端传过来的所有数据给了：request.data

之前的request.GET封装成：request.query_params

版本控制是做什么用的, 我们为什么要用?

开发是有周期，及版本迭代的，新版本上线，老版本也不能直接拉下，需要进行维护

版本控制是怎么实现的

version版本信息 赋值给了 request.version

版本控制方案 赋值给了 request.versioning_scheme

从而之后我们在视图中就可以通过request点属性，操作版本信息了

其实这个版本控制方案~就是我们配置的版本控制的类~~

也就是说，APIView通过这个方法初始化自己提供的组件~~

DRF提供了5种版本控制类的方法：

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from rest_framework import versioning

#最基础的版本控制类，给其他版本控制类提供一些共用方法
class BaseVersioning(object): ...
	  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):
        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):
        return _reverse(viewname, args, kwargs, request, format, **extra)

    #判断是否能访问当前版本
    def is_allowed_version(self, version):
        if not self.allowed_versions:
            return True
        #version存在并且等于默认版本或者version在允许访问的版本中
        #返回True or Fasle
        return ((version is not None and version == self.default_version) or
                (version in self.allowed_versions))

# 在accept请求头中配置版本信息
# accept代表希望返回的数据类型 可以携带版本信息
# Accept: application/json; version=1.0
class AcceptHeaderVersioning(BaseVersioning): ...
	pass
# 在url上携带版本信息
# url(r'^(?P<version>[v1|v2]+)/users/$',users_list,name='users-list')
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.

    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):
        #version_param  default_version DEFAULT_VERSION 都是在settings配置
        #version_param :url中获取值的key
        #default_version :默认版本
        #ALLOWED_VERSIONS：允许的版本
        version = kwargs.get(self.version_param, self.default_version)
        #如果version不存在,或者version不在允许访问的版本列表中
        if not self.is_allowed_version(version):
            #抛出异常
            raise exceptions.NotFound(self.invalid_version_message)
        #返回版本
        return version

# 把版本信息放在路由分发里，并把路由的namespace配置成版本
# url('^v1/', include('users.urls', namespace='v1'))
class NamespaceVersioning(BaseVersioning):
    pass

# 在我们的host上配置版本信息
# Host: v1.example.com
class HostNameVersioning(BaseVersioning):
    pass

# 在我们url上过滤条件上配置版本信息
# GET /something/?version=0.1 HTTP/1.1
class QueryParameterVersioning(BaseVersioning):
    pass

版本配置如何使用

不管基于那种方式都需要配置settings

setting配置

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REST_FRAMEWORK = {
    'DEFAULT_VERSION': 'v1',            # 默认版本
    'ALLOWED_VERSIONS': ['v1', 'v2'],   # 允许的版本
    'VERSION_PARAM': 'version'          # URL中获取值的key
}

基于url的get传参方式

/users?verson=v1

urls.py

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from web.views import TestView

urlpatterns = [
    url(r'^test/', TestView.as_view(),name='test'), #不同的方式此处路由方式不同
]

Views.py

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.versioning import QueryParameterVersioning


class TestView(APIView):
    versioning_class = QueryParameterVersioning  #不同的方式此处引用的类不通

    def get(self, request, *args, **kwargs):

        # 获取版本
        print(request.version)
        # 获取版本管理的类
        print(request.versioning_scheme)

        # 反向生成URL
        reverse_url = request.versioning_scheme.reverse('test', request=request)
        print(reverse_url)

        return Response('GET请求，响应内容')

    def post(self, request, *args, **kwargs):
        return Response('POST请求，响应内容')

    def put(self, request, *args, **kwargs):
        return Response('PUT请求，响应内容')

基于url的正则方式

/v1/users/

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# urls.py

from web.views import TestView

urlpatterns = [
    url(r'^(?P<version>[v1|v2]+)/test/', TestView.as_view(), name='test'),
]

# views.py

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.versioning import URLPathVersioning

class TestView(APIView):
    versioning_class = URLPathVersioning

基于主机名方法

v1.example.com

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# urls.py
from web.views import TestView

urlpatterns = [
    url(r'^test/', TestView.as_view(), name='test'),
]

# views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.versioning import URLPathVersioning

class TestView(APIView):
    versioning_class = HostNameVersioning

基于django路由系统的namespace

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# urls.py
from django.conf.urls import url, include
from web.views import TestView

urlpatterns = [
    url(r'^v1/', ([
                      url(r'test/', TestView.as_view(), name='test'),
                  ], None, 'v1')),
    url(r'^v2/', ([
                      url(r'test/', TestView.as_view(), name='test'),
                  ], None, 'v2')),
]

# views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.versioning import NamespaceVersioning


class TestView(APIView):
    versioning_class = NamespaceVersioning