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 = 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
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_allowed
return 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
PHP中文网2017-04-18 10:36:42
The dispath method is to find the function processing corresponding to the class view based on the request method: handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
The get_queryset method in ListView is called by other functions