python - django源码探究，as_view()的具体分发过程？

问题描述

最近在学习django的类视图，就打开源码学习下，但是对基类View的as_view方法不太理解，先把源码贴上来：

@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 = clsview.view_initkwargs = initkwargs# take name and docstring from classupdate_wrapper(view, cls, updated=())# and possible attributes set by decorators# like csrf_exempt from dispatchupdate_wrapper(view, cls.dispatch, assigned=())return view

因为最后涉及View的另外的一个方法dispatch，我也贴出这个方法源码：

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_allowedreturn handler(request, *args, **kwargs)

当类视图调用as_view方法时，会把请求时的request方法自动对应到相应的类方法上，比如request的get方法对应到类视图的get方法。

但是我看完源码的理解是：as_view仅仅能自动对应get和post（具体的request方法在类属性当中有个列表：http_method_names = [’get’, ’post’, ’put’, ’patch’, ’delete’, ’head’, ’options’, ’trace’]）等方法，如果我在类视图定义了自己的方法，那as_view并不能把我自定义的方法对应起来。

但是，同样是类视图，ListView当中却有get_queryset方法，那ListView在调用as_view方法时会自动调用这个get_queryset方法吗（它并不是request的方法是吧？）？

代码哪里提到了这个过程呢？

望大神指教~抱拳

问题解答

dispath方法里就是根据request的方法寻找class view对应的函数处理：handler = getattr(self, request.method.lower(), self.http_method_not_allowed)

ListView中的get_queryset方法是别的函数调用的