python - Tornado: Are there Request Filters? -

i looking @ tornado app , wondering how perform use case. need intercept every request before dispatching url handler , possibly return redirect. there way using tornado?

i wondering if tornado has concept of servlet filter. looks maybe input modifier decode_argumentdoes this? seems bit of hack filter request using method, haven't found else in documentation.

you have al least 3 options:

• use requesthandler.prepare() kamushin said.

• as said in this tornado issue comment:

  you can hook middleware, actually. httpserver request handlers callable objects (function, methods, or objects implement __call__). can write own handler passes on requests application

(example)

my_app = tornado.web.application(...)  def middleware(request):     # whatever transformation want here     my_app(request)  if __name__ == '__main__':     http_server = tornado.httpserver.httpserver(middleware)     # ... 

but notice that:

since tornado request handling can asynchronous, can't modify response in middleware, can @ least work request.

• use decorator. see this exaemple details on how implementing it.

• give try tornado-middleware or tmiddleware. carefull since they're 3 years old , may not work. can take @ code , learn it.