CBV 和 restful規範

知識點準備：

django的view

• FBV:基於函數的視圖

• CBV:基於類的視圖

  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 請求')
  
      def post(self,request,*args,**kwargs):
          return HttpResponse('POST 請求')
   
  

csrf_token

• 原理：基於中間件的process__view()做的，用戶發送get請求的時候django會給他返回一個隨機字符串，下次用戶發送post請求的時候，要求攜帶這個隨機字符串，驗證是否一樣，
• 免除：csrf_exempt
• 驗證：csrf_protect
• 為什麽不寫在process__request()裏面？
  因為它中間件要判斷視圖函數有沒有加免除或者驗證的裝飾器，如果在request裏面，他無法獲取哪些視圖函數加了裝飾器。

    # 第一種：給方法加
    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請求')
        
        def post(self, request, *args, **kwargs):
            return HttpResponse('POST請求')
             
    # 第二種：給類加
    @method_decorator(csrf_exempt,name='dispatch')
    class TeachersView(View):
    
        def get(self, request, *args, **kwargs):
            print('GET')
            return HttpResponse('GET請求')
        
        def post(self, request, *args, **kwargs):
            return HttpResponse('POST請求')
           
 

CBV源碼剖析

• FBV 和 CBV
  基於反射實現根據請求方式不同，執行不同的方法
  原理：
  • 路由 cls.as_view()-->view()-->self.dispatch()-->反射
  • 視圖：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請求')
  
         def post(self, request, *args, **kwargs):
             return HttpResponse('POST請求')
  
         def delete(self,request,*args,**kwargs):
             return HttpResponse('DELETE請求')
  
         def put(self,request,*args,**kwargs):
             return HttpResponse('PUT請求')
   
  

  • 繼承(多個類共用的功能，避免重復編寫)

     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請求')
  
         def post(self, request, *args, **kwargs):
             return HttpResponse('POST請求')
  
         def delete(self, request, *args, **kwargs):
             return HttpResponse('DELETE請求')
  
         def put(self, request, *args, **kwargs):
             return HttpResponse('PUT請求')

  restful規範

  十條規範

  • API與用戶的通信協議：https
    
  • 域名：
    • URL方式：www.abc.com/api/
    • 子域名方式(存在跨域問題) ：www.abc.com www.api.abc.com
  • 版本：www.abc.com/api/v1/
    
  • 面向資源(視網絡上的任何數據為資源，均使用名詞、可復數)：www.abc.com/api/v1/order/
    
  • 過濾，通過url傳遞搜索條件
    
  • 根據method不同進行不同的操作

    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('獲取訂單')
  
        def post(self, request, *args, **kwargs):
            return HttpResponse('創建訂單')
  
        def delete(self, request, *args, **kwargs):
            return HttpResponse('刪除訂單')
  
        def put(self, request, *args, **kwargs):
            return HttpResponse('更新訂單')
  

  • 狀態碼
    
  • 錯誤處理
    
  • 返回結果
    
  • 返回結果中就是url

django rest_framework

• 安裝：pip install djangorestframework
  
• 使用

  • 認證
    ```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')
              # 可以做用戶名密碼驗證
              if not token:
                  raise AuthenticationFailed('認證失敗')
              return (1, 2)
    
          def authenticate_header(self, request):
              pass
    
    
      class DogView(APIView):
          authentication_classes = [MyAuthentication]
    
          def get(self, request, *args, **kwargs):
              return HttpResponse('獲取小狗')
    
          def post(self, request, *args, **kwargs):
              return HttpResponse('創建小狗')
    
          def delete(self, request, *args, **kwargs):
              return HttpResponse('刪除小狗')
    
          def put(self, request, *args, **kwargs):
              return HttpResponse('更新小狗')

    ```

001---CBV和restful規範