CODEWITHSUNDEEP
google-app-enginepython-2.7urllib2facebook-opengraph
user1055761
user1055761

Reputation: 1071

Open Graph Action POST fails when called thru a google app engine based unpaid instance

urlopen fails with a 500 code and '{"error_code":1,"error_msg":"An unknown error occurred"}' error from Facebook when posting an Open Graph Action. I can get the code to work with other posts (e.g. posting a comment on a status using the graph API works fine). I can also get this action-post to work using curl. So this seems like a urllib2.urlopen issue when posting a form-data with a URL as one of the values.

Graph api post that works with curl : 

curl -F 'access_token=nnnnnn' -F 'object=https://abc.com/123' \
'https://graph.facebook.com/me/namespace:action' -k


Same Graph api post thru urllib2 which gives the error : 

from urllib2 import urlopen, Request, URLError

request = Request (url='http://graph.facebook.com/me/namespace:action';, 
                   data = urllib.urlencode(
                            {'object':'https://abc.com/123',
                             'access_token':'nnnnnnnn'
                            }, 
                   headers = {'Content-Type': 'application/x-www-form-urlencoded'}
          ) 
response = urlopen (request)

What could I be doing wrong ? (I am new to urllib2.urlopen. Btw, I originally tried urlfetch.fetch thru the urlfetch python module. That did not work either). I am using this thru goole app engine.

Upvotes: 1

Views: 473

Answers (1)

user1055761
user1055761

Reputation: 1071

After a fair amount of digging/trial-error, finally managed to solve this.

This is not an issue with urllib urlopen, but more of a Google App Engine nuance where when an action post on an open Graph URL is called - it causes Facebook to trigger a 'get' on the Object URL (synchronously).

So essentially the get is being called on app engine app while an active instance is already calling the FB graph URL. I am currently using an unpaid instance and this is causing an unexpected behavior such that FB to fails the OG post (I see the get on the logs going thru successfully, while the active post, so not sure what causes FB to fail - anybody with an insight, please share).

I got around this by 'taskqueue'ing urlopen/OG-action-post - and when this is called the second time (FB apparently caches the object the first time) it succeeds.

If anybody needs more details, get in touch and am more than happy to save you all the time and pain that I have already gone thru..

Upvotes: 1

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