一般请求的判断方法:
def view(request, *args, **kwargs): if request.method.lower() == 'get': do_something() if request.method.lower() == 'post': do_something()
使用View.as_view()代替判断:
class ClassName(View): ''' 继承View自动判断请求方法 ''' def post(): pass def get(): pass def other(): pass #调用方法 url(url, ClassName.as_view(), name)
设计思想:把视图函数的逻辑定义到类的方法里面去,然后在函数中实例化这个类,通过调用类的方法实现函数逻辑,而把逻辑定义在类中的一个好处就是可以通过继承复用这些方法。
class View(object): """ Intentionally simple parent class for all views. Only implements dispatch-by-method and simple sanity checking. """ http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace'] def __init__(self, **kwargs): """ Constructor. Called in the URLconf; can contain helpful extra keyword arguments, and other things. """ # Go through keyword arguments, and either save their values to our # instance, or raise an error. for key, value in six.iteritems(kwargs): setattr(self, key, value) @classonlymethod def as_view(cls, **initkwargs): """ Main entry point for a request-response process. """ for key in initkwargs: if key in cls.http_method_names: raise TypeError("You tried to pass in the %s method name as a " "keyword argument to %s(). Don't do that." % (key, cls.__name__)) if not hasattr(cls, key): raise TypeError("%s() received an invalid keyword %r. as_view " "only accepts arguments that are already " "attributes of the class." % (cls.__name__, key)) def view(request, *args, **kwargs): self = cls(**initkwargs) if hasattr(self, 'get') and not hasattr(self, 'head'): self.head = self.get self.request = request self.args = args self.kwargs = kwargs return self.dispatch(request, *args, **kwargs) view.view_class = cls view.view_initkwargs = initkwargs # take name and docstring from class update_wrapper(view, cls, updated=()) # and possible attributes set by decorators # like csrf_exempt from dispatch update_wrapper(view, cls.dispatch, assigned=()) return view def dispatch(self, request, *args, **kwargs): # Try to dispatch to the right method; if a method doesn't exist, # defer to the error handler. Also defer to the error handler if the # request method isn't on the approved list. if request.method.lower() in self.http_method_names: handler = getattr(self, request.method.lower(), self.http_method_not_allowed) else: handler = self.http_method_not_allowed return handler(request, *args, **kwargs) def http_method_not_allowed(self, request, *args, **kwargs): logger.warning( 'Method Not Allowed (%s): %s', request.method, request.path, extra={'status_code': 405, 'request': request} ) return http.HttpResponseNotAllowed(self._allowed_methods()) def options(self, request, *args, **kwargs): """ Handles responding to requests for the OPTIONS HTTP verb. """ response = http.HttpResponse() response['Allow'] = ', '.join(self._allowed_methods()) response['Content-Length'] = '0' return response def _allowed_methods(self): return [m.upper() for m in self.http_method_names if hasattr(self, m)]