1.REST framework版本控制的流程分析
1.1 determine_version方法的执行流程
首先,请求到达REST framework的CBV,执行CBV中的dispatch方法再次封装完成request后,执行initial方法.
在REST framework中的版本控制就是在initial函数中调用determine_version方法完成的
来看看源码
initial方法的源码:
def initial(self, request, *args, **kwargs):
"""
Runs anything that needs to occur prior to calling the method handler.
"""
self.format_kwarg = self.get_format_suffix(**kwargs)
# Perform content negotiation and store the accepted info on the request
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
# Determine the API version, if versioning is in use.
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
# Ensure that the incoming request is permitted
self.perform_authentication(request)
self.check_permissions(request)
self.check_throttles(request)determine_version方法的源码
def determine_version(self, request, *args, **kwargs):
if self.versioning_class is None: # 如果versioning_class为空则返回一个None的元组
return (None, None)
scheme = self.versioning_class()
return (scheme.determine_version(request, *args, **kwargs), scheme)determine_version方法中的versioning_class方法又是从哪里来的呢
1.2 versioning_class的由来
在UserView视图函数中没有定义versioning_class,那就要到UserView的父类APIView中去找
在APIView类中定义了versioning_class的信息
class APIView(View):
renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
metadata_class = api_settings.DEFAULT_METADATA_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS在视图函数中打印versioning_class
None可以看到默认设置的versioning_class的值是None,这说明我们可以在视图函数中为versioning_class设置一个值
在detemine_version函数的源码中,可以看到versioning_class后面加了一个括号,所以versioning_class是一个函数或一个类
如果versioning_class是一个函数,那么执行versioning_class后会有一个返回值
如果versioning_class是一个类,那么versioning_class加括号就实例化一个类从rest_framework中导入versioning模块
from rest_framework import versioning然后进入versioning模块,可以看到这个versioning中定义了6个类
这6个类是BaseVersioning,AcceptHeaderVersioning,URLPathVersioning,NamespaceVersioning,HostNameVersioning,QueryParameterVersioning
而且还可以看到BaseVersioning类是其余5个类的父类.
并且这其余的5个类,每个类中都有一个determine_version方法
在项目的视图函数中导入其中任意一个类,打印versioning_class
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from django.views import View
from rest_framework.versioning import QueryParameterVersioning
class UsersView(APIView):
versioning_class=QueryParameterVersioning
def get(self,request,*args,**kwargs):
print(self.versioning_class) #打印versioning_class
return HttpResponse("aaaa")打印结果
<class 'rest_framework.versioning.QueryParameterVersioning'>所以versioning_class是一个类,并且versioning_class类中有一个determine_version方法
1.3 REST framework版本控制的流程总结
在initial方法中,执行完determine_version后的返回值被赋值给version, scheme这两个变量
def initial(self, request, *args, **kwargs):
self.format_kwarg = self.get_format_suffix(**kwargs)
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
self.perform_authentication(request)
self.check_permissions(request)
self.check_throttles(request)这两个变量又把determine_version方法的返回值赋值给request.version, request.versioning_scheme这两个变量
在视图函数中打印这两个变量
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.versioning import QueryParameterVersioning
class UsersView(APIView):
versioning_class=QueryParameterVersioning
def get(self,request,*args,**kwargs):
print(self.versioning_class)
print("request.version:",request.version)
print("request.versioning_scheme:",request.versioning_scheme)
return HttpResponse("aaaa")打印结果
<class 'rest_framework.versioning.QueryParameterVersioning'>
request.version: None
request.versioning_scheme: <rest_framework.versioning.QueryParameterVersioning object at 0x00000000057722B0>2. REST framework获取版本的方法
在上面的流程分析中,versioning模块中定义了6个类
这6个类是BaseVersioning,AcceptHeaderVersioning,URLPathVersioning,NamespaceVersioning,HostNameVersioning,QueryParameterVersioning
BaseVersioning类是其余5个类的父类,REST framework获取版本调用的就是这5个类
2.1 QueryParameterVersioning:基于url的get传参方式
在settings.py文件的INSTALLED_APPS配置项中引入rest-framework
INSTALLED_APPS = [
...
'rest_framework',
]配置路由表
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^users/$',views.UsersView.as_view()),
]视图函数配置获取版本方式为QueryParameterVersioning
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.versioning import QueryParameterVersioning
class UsersView(APIView):
versioning_class=QueryParameterVersioning
def get(self,request,*args,**kwargs):
# print("request:",request.__dict__)
print("request.version:",request.version) # 打印版本
# print(request.version.scheme)
# print(request.versioning_scheme.reverse("test1",request=request))
# print(request.versioning_scheme.reverse(viewname="test1",request=request))
return HttpResponse("aaaa") 在浏览器中输入http://127.0.0.1:8000/users/?version=v1地址,服务端打印结果
request.version: v1再把浏览器中的url地址更换为http://127.0.0.1:8000/users/?version=v5,刷新浏览器,服务端打印结果
request.version: v52.2 URLPathVersioning:基于url的正则方式
配置url路由信息
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^(?P<version>\w+)/users/$',views.UsersView.as_view()),
]视图函数配置获取版本方式为URLPathVersioning
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.versioning import URLPathVersioning
class UsersView(APIView):
versioning_class=URLPathVersioning
def get(self,request,*args,**kwargs):
print("request.version:",request.version) # 打印版本
return HttpResponse("aaaa")在浏览器中输入http://127.0.0.1:8000/v1/users/地址,服务端打印结果
request.version: v1再把浏览器中的url地址更换为http://127.0.0.1:8000/v10/users/,刷新浏览器,服务端打印结果
request.version: v102.3 AcceptHeaderVersioning:基于accept请求头方式获取版本信息
在settings.py文件中添加如下配置
REST_FRAMEWORK = {
'VERSION_PARAM': "version", # 版本的参数,在url中可以体现
'DEFAULT_VERSION': 'V1', # 默认的版本
'ALLOWED_VERSIONS': ['v1', 'v2','v3'] # 允许的版本
}urls.py设定为
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^users/$',views.UsersView.as_view()),
]视图函数定义
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.versioning import AcceptHeaderVersioning
class UsersView(APIView):
versioning_class=AcceptHeaderVersioning
def get(self,request,*args,**kwargs):
print("request.version:",request.version) # 获取版本信息
return HttpResponse("aaaa")用浏览器打开http://127.0.0.1:8000/users/的url地址
request.version: V1
由于在settings.py文件中已经设定了默认的版本是v1,所以在服务端后台获取到的版本是v1把settings.py中定义的默认版本更改变v2或者v3,再次刷新浏览器,后台打印的版本信息又会跟着改变
request.version: V22.4 NamespaceVersioning:基于django路由系统的namespace
urls.py设定为
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^v1/users/',([url(r'test/',views.UsersView.as_view(),name='test1')],None,'v1')),
url(r'^v2/users/',([url(r'test/',views.UsersView.as_view(),name='test2')],None,'v2')),
]视图函数定义
from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.versioning import NamespaceVersioning
class UsersView(APIView):
versioning_class=NamespaceVersioning
def get(self,request,*args,**kwargs):
print("request.version:",request.version) # 获取版本信息
return HttpResponse("aaaa")用浏览器打开http://127.0.0.1:8000/v1/users/test/的url地址
request.version: V1把url的地址更换为http://127.0.0.1:8000/v2/users/test/,刷新浏览器,后台打印信息如下
request.version: V22.5 HostNameVersioning由于要更换电脑的主机名称,所以这里不再进行测试
3. versioning_class的全局配置
在视图函数中定义versioning_class,只能作用于单个类,
如果想整个项目都使用同一种方法来进行版本控制,就可以在settings.py文件中定义全局的versioning_class
在settings.py中配置默认的versioning_class为URLPathVersioning
REST_FRAMEWORK={
'DEFAULT_VERSIONING_CLASS':'rest_framework.versioning.URLPathVersioning',
}在前面查看到BaseVersioning的源码时,可以看到还有几个参数可以在settings.py文件中定义的
class BaseVersioning(object):
default_version = api_settings.DEFAULT_VERSION
allowed_versions = api_settings.ALLOWED_VERSIONS
version_param = api_settings.VERSION_PARAM再来看看这几个参数配置项的作用
REST_FRAMEWORK={ # 默认使用URLPathVersioning类来获取版本信息
'DEFAULT_VERSIONING_CLASS':'rest_framework.versioning.URLPathVersioning',
'VERSION_PARAM':"version", # 版本的参数,在url中可以体现
'DEFAULT_VERSION':'V1', # 默认的版本
'ALLOWED_VERSIONS':['v1','v2'] # 允许的版本
}修改urls.py文件,使url可以匹配任意长度的字符url
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^(?P<version>\w+)/users/$',views.UsersView.as_view()),
]在浏览器中分别输入http://127.0.0.1:8000/v1/users/和http://127.0.0.1:8000/v2/users/
都可以获取到正确的响应信息
再在浏览器中输入http://127.0.0.1:8000/v3/users/时,浏览器中出现了报错
从这里可以知道,在settings.py文件中设定的url中允许的版本只能是v1或v2,在浏览器中输入的版本是v3,所以就会出现错误了
