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Handle webapp2 404 error in requesthandler class method instead of function

I am using the webapp2 environment in the Google App Engine (Python). The webapp2 exception handling: exceptions in a WSGI application describes how to handle 404 errors in a function:

import logging
import webapp2

def handle_404(request, response, exception):
    logging.exception(exception)
    response.write('Oops! I could swear this page was here!')
    response.set_status(404)

def handle_500(request, response, exception):
    logging.exception(exception)
    response.write('A server error occurred!')
    response.set_status(500)

app = webapp2.WSGIApplication([
    webapp2.Route('/', handler='handlers.HomeHandler', name='home')
])
app.error_handlers[404] = handle_404
app.error_handlers[500] = handle_500

How can I handle 404 error in a class webapp2.RequestHandlerin a method of .get()this class?

Edit:

I want to call RequestHandlerto access the session ( request.session). Otherwise, I cannot transfer the current user to the 404 error page template. That is, on the StackOverflow 404 page you can see your username. I would like to show the username of the current user on page 404 of the page of my site. Is this possible in a function or should it be RequestHandler?

@proppy:

class Webapp2HandlerAdapter(webapp2.BaseHandlerAdapter):
    def __call__(self, request, response, exception):
        request.route_args = {}
        request.route_args['exception'] = exception
        handler = self.handler(request, response)
        return handler.get()

class Handle404(MyBaseHandler):
    def get(self):
        self.render(filename="404.html",
            page_title="404",
            exception=self.request.route_args['exception']
        )

app = webapp2.WSGIApplication(urls, debug=True, config=config)
app.error_handlers[404] = Webapp2HandlerAdapter(Handle404)
+3
1

:

  • error_handlers (request, response, exception)
  • RequestHandler (request, response)

Webapp2HandlerAdapter, webapp2.RequestHandler .

class Webapp2HandlerAdapter(BaseHandlerAdapter):
    """An adapter to dispatch a ``webapp2.RequestHandler``.

    The handler is constructed then ``dispatch()`` is called.
    """

    def __call__(self, request, response):
        handler = self.handler(request, response)
        return handler.dispatch()

route_args.

+3

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