Python Flask failing on combined GET and POST request

Question

I'm writing a function in Python Flask to deal with the oauth2 call backs of multiple api's.

The function as it stands is:

@app.route('/external_api/<api>/oauth2callback', methods=['POST', 'GET'])
def gdrive_oauth2callback(api):
    toReturn = external_api.APIs[api]['lib'].oauth2callback(os.path.join(APP_OAUTH, str(api + '_id.json')))
    userSession = UserSession()
    userSession.addUserAuth(api)
    return toReturn

However this causes a build error:

raise BuildError(endpoint, values, method)
BuildError: ('gdrive_oauth2callback', {}, None)

I'm confused as to why this is happening, as when i replace the api variable with the string 'gdrive' no error is created and it works perfectly. I'm calling the function in the same manner on both occasions (example.com/external_api/gdrive/oauth2callback), I'm wondering if Flask is unable to deal with both a POST request and a GET request at the same time, and if anyone else has had the same issue?

The full error log is below:

ERROR:app:Exception on /external_api/gdrive/connect [GET]
Traceback (most recent call last):
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/app/app/views.py", line 43, in gdrive_connect
toReturn = external_api.APIs[api]['lib'].makeConnection()
File "/app/app/external_api/gdrive/api.py", line 14, in makeConnection
return flask.redirect(flask.url_for('gdrive_oauth2callback'))
File "/app/.heroku/python/lib/python2.7/site-packages/flask/helpers.py", line 312, in url_for
return appctx.app.handle_url_build_error(error, endpoint, values)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1641, in handle_url_build_error
reraise(exc_type, exc_value, tb)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/helpers.py", line 305, in url_for
force_external=external)
File "/app/.heroku/python/lib/python2.7/site-packages/werkzeug/routing.py", line 1616, in build
raise BuildError(endpoint, values, method)
BuildError: ('gdrive_oauth2callback', {}, None) - at=info method=GET path

If anyone could give me any pointers on this that would be great! Thanks!

Answer 1

I think that flask must not be failing, if you take a look to this example, it works perfectly, http://flask.pocoo.org/snippets/62/ .

I tried:

from flask import Flask
app = Flask(__name__)

@app.route("/<name>",methods=['POST', 'GET'])
def hello(name):
   return "Hello World!"+name

if __name__ == "__main__":
   app.run()

and it works fine on post and get requests. I know that isnt enougth but it shows what the problem probably isn't.