• jQuery火箭图标返回顶部代码


    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)]

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  • 原文地址:https://www.cnblogs.com/MayDayTime/p/9750182.html
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