routing.py 文件源码

def dispatch(self, view_func, path_info=None, method=None,
                 catch_http_exceptions=False):
        """Does the complete dispatching process.  `view_func` is called with
        the endpoint and a dict with the values for the view.  It should
        look up the view function, call it, and return a response object
        or WSGI application.  http exceptions are not caught by default
        so that applications can display nicer error messages by just
        catching them by hand.  If you want to stick with the default
        error messages you can pass it ``catch_http_exceptions=True`` and
        it will catch the http exceptions.

        Here a small example for the dispatch usage::

            from werkzeug.wrappers import Request, Response
            from werkzeug.wsgi import responder
            from werkzeug.routing import Map, Rule

            def on_index(request):
                return Response('Hello from the index')

            url_map = Map([Rule('/', endpoint='index')])
            views = {'index': on_index}

            @responder
            def application(environ, start_response):
                request = Request(environ)
                urls = url_map.bind_to_environ(environ)
                return urls.dispatch(lambda e, v: views[e](request, **v),
                                     catch_http_exceptions=True)

        Keep in mind that this method might return exception objects, too, so
        use :class:`Response.force_type` to get a response object.

        :param view_func: a function that is called with the endpoint as
                          first argument and the value dict as second.  Has
                          to dispatch to the actual view function with this
                          information.  (see above)
        :param path_info: the path info to use for matching.  Overrides the
                          path info specified on binding.
        :param method: the HTTP method used for matching.  Overrides the
                       method specified on binding.
        :param catch_http_exceptions: set to `True` to catch any of the
                                      werkzeug :class:`HTTPException`\s.
        """
        try:
            try:
                endpoint, args = self.match(path_info, method)
            except RequestRedirect as e:
                return e
            return view_func(endpoint, args)
        except HTTPException as e:
            if catch_http_exceptions:
                return e
            raise