How to redirect the url after logging into Facebook?

Question

I have created a django application with a Facebook connect to the application. Now when i click on the Facebook login button, the oauth page pop ups. When i give the userna

Answer 1

I suppose you are using the JS Facebook library if you say that the oauth just pop ups. I would go the simpler oauth redirect way, using a the following :

def build_authentication_redirect(self):
            args = {}
            args["client_id"]=self.app_id
            args["redirect_uri"]=self.redirect_uri
            args["scope"]=",".join(self.req_perms)
            redirect_url = "https://www.facebook.com/dialog/oauth?"+urllib.urlencode(args)
            redirect_code = """
                    
            """ % redirect_url;
            return HttpResponse(redirect_code,mimetype="text/html")

Where self.app_id is your facebook app id. Where self.redirect_uri is the url the user will be redirected after login. Where self.scope is built from self.req_perms which is an array of the required permissions.

After that they user will be redirected to redirect_uri with the access token in post 'signed_request' parameter, you can use the following function to decode it :

def load_signed_request(self, signed_request):
            """Load the user state from a signed_request value"""
            sig, payload = signed_request.split(u'.', 1)
            sig = self.base64_url_decode(sig)
            data = json.loads(self.base64_url_decode(payload))

            expected_sig = hmac.new(self.app_secret, msg=payload, digestmod=hashlib.sha256).digest()

            # allow the signed_request to function for upto 1 day
            if sig == expected_sig and data[u'issued_at'] > (time.time() - 86400):
                    return data.get(u'user_id'), data.get(u'oauth_token')
            else:
                    return None,None

Example :

sigreq =request.POST.get('signed_request', None)
user_id,access_token = load_signed_request(sigreq)

Again you will need self.app_secret and the following function :

@staticmethod
    def base64_url_decode(data):
            data = data.encode(u'ascii')
            data += '=' * (4 - (len(data) % 4))
            return base64.urlsafe_b64decode(data)

I had a lot of trouble with FB JS login and auth, especially on different browsers, this way is the more robust way I could find :)

Btw If you want my facebook.py file I can put it available online somewhere ... It even has a @fbsig_required and @fbsig_redirect view decorators ...

Oh Also here are my imports :

import cgi
import hashlib
import time
import urllib
import base64
import datetime
import hmac

from django.conf import settings
from django.http import HttpResponseRedirect,HttpResponse,HttpResponseNotFound