001---CBV和restful规范

CBV 和 restful规范

知识点准备：

django的view

• FBV:基于函数的视图

• CBV:基于类的视图

  urls.py
  
  from django.urls import path
  from app01.views import StudentsView
  
  urlpatterns = [
  path('students/ ',StudentsView.as_view()),
  ]
  
  views.py
  
  from django.views import View
  from django.shortcuts import HttpResponse
  
  class StudentsView(View):
  
      def get(self,request,*args,**kwargs):
          return HttpResponse('GET 请求')
  
      def post(self,request,*args,**kwargs):
          return HttpResponse('POST 请求')

csrf_token

• 原理：基于中间件的process__view()做的，用户发送get请求的时候django会给他返回一个随机字符串，下次用户发送post请求的时候，要求携带这个随机字符串，验证是否一样，
• 免除：csrf_exempt
• 验证：csrf_protect
• 为什么不写在process__request()里面？
  因为它中间件要判断视图函数有没有加免除或者验证的装饰器，如果在request里面，他无法获取哪些视图函数加了装饰器。

    # 第一种：给方法加
    from django.views import View
    from django.views.decorators.csrf import csrf_exempt, csrf_protect
    from django.utils.decorators import method_decorator
        
        
    class StudentsView(View):
    
        @method_decorator(csrf_exempt)
        def dispatch(self, request, *args, **kwargs):
            return super(StudentsView, self).dispatch(request, *args, **kwargs)
        
        def get(self, request, *args, **kwargs):
            
            print('GET')
            return HttpResponse('GET请求')
        
        def post(self, request, *args, **kwargs):
            return HttpResponse('POST请求')
             
    # 第二种：给类加
    @method_decorator(csrf_exempt,name='dispatch')
    class TeachersView(View):
    
        def get(self, request, *args, **kwargs):
            print('GET')
            return HttpResponse('GET请求')
        
        def post(self, request, *args, **kwargs):
            return HttpResponse('POST请求')
           

CBV源码剖析

• FBV 和 CBV
  基于反射实现根据请求方式不同，执行不同的方法
  原理：
  • 路由 cls.as_view()-->view()-->self.dispatch()-->反射
  • 视图：get post delete put……
  • 流程

     class StudentsView(View):
  
         def dispatch(self, request, *args, **kwargs):
             # return HttpResponse('dispath')
             func = getattr(self,request.method.lower())
             return func(request, *args, **kwargs)
  
         def get(self, request, *args, **kwargs):
             return HttpResponse('GET请求')
  
         def post(self, request, *args, **kwargs):
             return HttpResponse('POST请求')
  
         def delete(self,request,*args,**kwargs):
             return HttpResponse('DELETE请求')
  
         def put(self,request,*args,**kwargs):
             return HttpResponse('PUT请求')

  • 继承(多个类共用的功能，避免重复编写)

     class MyBaseView(object):
         def dispatch(self, request, *args, **kwargs):
             print('before')
             func = super(MyBaseView, self).dispatch(request, *args, **kwargs)
             print('after')
             return func
  
  
     class StudentsView(MyBaseView, View):
  
         def get(self, request, *args, **kwargs):
             print('GET')
             return HttpResponse('GET请求')
  
         def post(self, request, *args, **kwargs):
             return HttpResponse('POST请求')
  
         def delete(self, request, *args, **kwargs):
             return HttpResponse('DELETE请求')
  
         def put(self, request, *args, **kwargs):
             return HttpResponse('PUT请求')

  restful规范

  十条规范

  • API与用户的通信协议：https
    
  • 域名：
    • URL方式：www.abc.com/api/
    • 子域名方式(存在跨域问题) ：www.abc.com www.api.abc.com
  • 版本：www.abc.com/api/v1/
    
  • 面向资源(视网络上的任何数据为资源，均使用名词、可复数)：www.abc.com/api/v1/order/
    
  • 过滤，通过url传递搜索条件
    
  • 根据method不同进行不同的操作

    from django.urls import path
    from app01.views import OrderView
  
    urlpatterns = [
        path('order/',OrderView.as_view()),
    ]
  
    class OrderView(View):
  
        def get(self, request, *args, **kwargs):
            return HttpResponse('获取订单')
  
        def post(self, request, *args, **kwargs):
            return HttpResponse('创建订单')
  
        def delete(self, request, *args, **kwargs):
            return HttpResponse('删除订单')
  
        def put(self, request, *args, **kwargs):
            return HttpResponse('更新订单')
  

  • 状态码
    
  • 错误处理
    
  • 返回结果
    
  • 返回结果中就是url

django rest_framework

• 安装：pip install djangorestframework
  
• 使用

  • 认证
    ```python
    from rest_framework.views import APIView
    from rest_framework.exceptions import AuthenticationFailed

      class MyAuthentication(object):
    
          def authenticate(self, request):
    
              token = request._request.GET.get('token')
              # 可以做用户名密码验证
              if not token:
                  raise AuthenticationFailed('认证失败')
              return (1, 2)
    
          def authenticate_header(self, request):
              pass
    
    
      class DogView(APIView):
          authentication_classes = [MyAuthentication]
    
          def get(self, request, *args, **kwargs):
              return HttpResponse('获取小狗')
    
          def post(self, request, *args, **kwargs):
              return HttpResponse('创建小狗')
    
          def delete(self, request, *args, **kwargs):
              return HttpResponse('删除小狗')
    
          def put(self, request, *args, **kwargs):
              return HttpResponse('更新小狗')

    ```