Django—基本视图-View

根视图View类

@classonlymethod
 def as_view(cls, **initkwargs):
 """Main entry point for a request-response process."""
 # 参数检查
 for key in initkwargs:
 if key in cls.http_method_names: # 参数名不能是指定http的方法名
 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): # 参数名必须是类已有属性
 raise TypeError("%s() received an invalid keyword %r. as_view "
 "only accepts arguments that are already "
 "attributes of the class." % (cls.__name__, key))
 # 视图处理函数
 def view(request, *args, **kwargs):
 self = cls(**initkwargs) # 实例化当前类的对象
 if hasattr(self, 'get') and not hasattr(self, 'head'):
 self.head = self.get
 self.setup(request, *args, **kwargs)
 if not hasattr(self, 'request'):
 raise AttributeError(
 "%s instance has no 'request' attribute. Did you override "
 "setup() and forget to call super()?" % cls.__name__
 )
 # 方法派发
 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 # 返回视图函数@classonlymethod