rest_framework框架

# 路由部分
from django.conf.urls import url,include
from . import views

urlpatterns = [
    url(r‘^book/$‘,views.BookSerializers.as_view()),
]

# 视图部分
class BookSerializers(View):

    def get(self,request):
        return HttpResponse("GET")

    def post(self,request):
        return HttpResponse("POST")

 1  @classonlymethod
 2     def as_view(cls, **initkwargs):
 3         """
 4         Main entry point for a request-response process.
 5         """
 6         for key in initkwargs:
 7             if key in cls.http_method_names:
 8                 raise TypeError("You tried to pass in the %s method name as a "
 9                                 "keyword argument to %s(). Don‘t do that."
10                                 % (key, cls.__name__))
11             if not hasattr(cls, key):
12                 raise TypeError("%s() received an invalid keyword %r. as_view "
13                                 "only accepts arguments that are already "
14                                 "attributes of the class." % (cls.__name__, key))
15 
16         def view(request, *args, **kwargs):
17             self = cls(**initkwargs)
18             if hasattr(self, ‘get‘) and not hasattr(self, ‘head‘):
19                 self.head = self.get
20             self.request = request
21             self.args = args
22             self.kwargs = kwargs
23             #为捕获到异常，最后实际上就是执行dispatch()方法
24             return self.dispatch(request, *args, **kwargs)
25         view.view_class = cls
26         view.view_initkwargs = initkwargs
27 
28         # take name and docstring from class
29         update_wrapper(view, cls, updated=())
30 
31         # and possible attributes set by decorators
32         # like csrf_exempt from dispatch
33         update_wrapper(view, cls.dispatch, assigned=())
34         return view                    

1     def dispatch(self, request, *args, **kwargs):
2         # Try to dispatch to the right method; if a method doesn‘t exist,
3         # defer to the error handler. Also defer to the error handler if the
4         # request method isn‘t on the approved list.
　　　　　　#根据请求的方法遍历http_method_names进行匹配,匹配成功返回子类的请求方法的方法名，供路由去执行该方法

5         if request.method.lower() in self.http_method_names:
6             handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
7         else:
8             handler = self.http_method_not_allowed
9         return handler(request, *args, **kwargs)