Django Rest Framework的request源码解析

1. Django CBV下的request

# 路由层
from app import views
urlpatterns = [
    url(r'^cbv/', views.CBVTest.as_view()),
]

# 视图层
from django.shortcuts import render, HttpResponse
from django.views import View
class CBVTest(View):
    # 通过调度(dispatch)分发请求
    def dispatch(self, request, *args, **kwargs):
        pass
        super().dispatch(request, *args, **kwargs)
        pass

    def get(self, request):
        return render(request, 'cbv.html')

    def post(self, request):
        return HttpResponse('cbv post method')

<!-- 模板层 -->
<form action="/cbv/" method="post">
    {% csrf_token %}
    <input type="text" name="usr">
    <button type="submit">提交</button>
</form>

2. DRF的简单示例

# 1）安装drf：pip3 install djangorestframework
# 2）settings.py注册app：INSTALLED_APPS = [..., 'rest_framework']
# 3）基于cbv完成满足RSSTful规范的接口

# 路由层
from app import views
urlpatterns = [
    url(r'^drf/', views.Drf.as_view()),
]

# 视图层
from rest_framework.views import APIView
from rest_framework.response import Response

user_list = [{'id': 1, 'name': 'Bob'}, {'id': 2, 'name': 'Tom'}]
class Drf(APIView):
    def get(self, request, *args, **kwargs):
        return Response({
            'status': 0,
            'msg': 'ok',
            'results': user_list
        })
    def post(self, request, *args, **kwargs):
        # request对formdata，urlencoded，json三个格式参数均能解析
        name = request.data.get('name')
        id = len(user_list) + 1
        user = {'id': id, 'name': name}
        user_list.append(user)
        return Response({
            'status': '0',
            'msg': 'ok',
            'results': user
        })

3.request流程

# as_view()
    # 核心走了父类as_view
    view = super(APIView, cls).as_view(**initkwargs)
    # 返回的是局部禁用csrf认证的view视图函数
    return csrf_exempt(view)
    
# dispatch(self, request, *args, **kwargs)
    # 二次封装request对象
    request = self.initialize_request(request, *args, **kwargs)
    # 自定义request规则
    self.initial(request, *args, **kwargs)
    
# initialize_request(self, request, *args, **kwargs)
    # 原生request封装在request._request
    
# initial(self, request, *args, **kwargs)
    # 认证
    self.perform_authentication(request)
    # 权限
    self.check_permissions(request)
    # 频率
    self.check_throttles(request)

走一遍：

1 as_view()

查看APIview 源码，我们可以发现它的 as_view()方法同样返回了view(),但是它的view其实是执行了父类的as_view()方法，所以也就是说APIView的as_view()方法依然返回了View的view() 如下图：

 2. dispath()

进而继续跟进源码，View的view()方法返回self.dispatch()，但此时的self不是 View的实例对象，而是APIView的对象，所以我们需要去看APIView中的dispatch 方法，如下图所示