Tornado POST 405: Method Not Allowed

Question

For some reason, I am not able to use POST methods in tornado.

Even the hello_world example does not work when I change GET to POST.

import tornado.ioloop
import tornado.web

class MainHandler(tornado.web.RequestHandler):
    def post(self):
        self.write("Hello, world")

application = tornado.web.Application([
    (r"/", MainHandler),
])

if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

It throws "405 method not allowed". Any suggestions?

Canea

Answer 1

You still need get if you want access the page, because access the page using browser request with GET method.

import tornado.ioloop
import tornado.web

class MainHandler(tornado.web.RequestHandler):
    def post(self):
        self.write("Hello, world")
    get = post # <--------------

application = tornado.web.Application([
    (r"/", MainHandler),
])

if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

Hildegaard

Making get and post behave the same is something I have to do often. Is writing get = post considered the correct way to do it? – Christen

@andyboot, If behaviors of both methods are same, yes. – Hildegaard

this still doesn't work for me WARNING:tornado.access:405 OPTIONS tested from both file:// and localhost – Wines

@SephReed, Please post a separated question with details. BTW, OPTIONS , not GET ? Try get = options = post if you want OPTIONS http method. – Hildegaard

Yeah, it's pretty odd. I have the word OPTIONS literally nowhere. Question created: #44900782 – Wines

I can't believe this actually works... But it does and it just saved me some miserable hours of debugging ... – Meath

Answer 2

Falsetru answer is a useful hint and yes, what you need is exactly a get method. But no, I don't think get and post method should behave the same. The semantics of the two methods is different. Please have a look at the HTTP specs http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html and consider Brabster answer to this question What is the difference between a HTTP-Get and HTTP-POST and why is HTTP-POST weaker in terms of security.

(sorry, my sentence should be better a comment to falsetru answer but my reputation don't allow)

Mycenae

Answer 3

recently， I have met the same problem. the following codes are my solutions:

import tornado.ioloop
import tornado.web

class MainHandler(tornado.web.RequestHandler):
    def set_default_headers(self):
    print('set headers!!')
    self.set_header('Access-Control-Allow-Origin', '*')
    self.set_header('Access-Control-Allow-Headers', '*')
    self.set_header('Access-Control-Max-Age', 1000)
    self.set_header('Content-type', 'application/json')
    self.set_header('Access-Control-Allow-Methods', 'POST, GET, OPTIONS')
    self.set_header('Access-Control-Allow-Headers',
                    'Content-Type, Access-Control-Allow-Origin, Access-Control-Allow-Headers, X-Requested-By, Access-Control-Allow-Methods')


def OPTIONS(self):
    pass

def post(self):
    self.write("Hello, world")

application = tornado.web.Application([
(r"/", MainHandler),
])

if __name__ == "__main__":`enter code here`
 application.listen(8888)
 tornado.ioloop.IOLoop.instance().start()

Hendershot

I tried this - and now the page displays the html page as text instead of rendering it. I'm on chrome on iphone 7 – Schmaltzy

For my app the line Content-type, 'application-json' is wrong: please note that in your answer it should not be included for some apps. – Schmaltzy

Answer 4

The example code you gave in your question DOES work. Just be sure to send a POST instead of GET using Curl or Postman, for instance. If you point a web-browser to the URL it will attempt a GET, which you haven't defined.

You may not want to define a GET for the URL. It is perfectly legal to have a POST-only URL, and Tornado certainly allows you to. The POST url might be a common submission point for forms loaded from many other locations.

Elias

It doesn't work. Please stop saying it works, because it doesn't, this problem is extremely annoying already. POST requests from either Postman or cURL don't work either. This is a deep issue within Tornado. – Phlegmy

Well, I tested it once again on yet another machine. I copy/pasted the code from the question block. Then I ran it. Then I ran a POST with Postman in Chrome. Looks fine. When I change postman to do a GET on the example I get a 405 error. I'll try and paste an image in my original answer. – Elias