Ever since Facebook launched graph.facebook.com, I’ve been wanting to check it out and see just how superior it is to Facebook Connect. It turns out it was pretty easy to authenticate myself from python using OAuth 2. So I wrote a little script that spits out my feed on the command line.

If you’ve ever felt frustrated implementing an OAuth client before, rest assured that OAuth 2 is one million times easier to work with than OAuth 1. You don’t have to keep track of all these different tokens or worry about generating signatures in just the right way. The one gotcha here is that you need a web server for the user to be redirected to after they authorize your application with Facebook. Fortunately, python makes it really easy to start up a mini webserver for the purposes of OAuth.

Here is the script in 75 lines of python. If you want to try it out yourself, you’ll have to register an application with Facebook at http://developers.facebook.com/setup/.

#!/usr/bin/python2.6
import os.path
import json
import urllib2
import urllib
import urlparse
import BaseHTTPServer
import webbrowser

APP_ID = 'your-app-id-here'
APP_SECRET = 'your-app-secret-here'
ENDPOINT = 'graph.facebook.com'
REDIRECT_URI = 'http://127.0.0.1:8080/'
ACCESS_TOKEN = None
LOCAL_FILE = '.fb_access_token'
STATUS_TEMPLATE = u"{name}\033[0m: {message}"

def get_url(path, args=None):
    args = args or {}
    if ACCESS_TOKEN:
        args['access_token'] = ACCESS_TOKEN
    if 'access_token' in args or 'client_secret' in args:
        endpoint = "https://"+ENDPOINT
    else:
        endpoint = "http://"+ENDPOINT
    return endpoint+path+'?'+urllib.urlencode(args)

def get(path, args=None):
    return urllib2.urlopen(get_url(path, args=args)).read()

class RequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):

    def do_GET(self):
        global ACCESS_TOKEN
        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.end_headers()

        code = urlparse.parse_qs(urlparse.urlparse(self.path).query).get('code')
        code = code[0] if code else None
        if code is None:
            self.wfile.write("Sorry, authentication failed.")
            sys.exit(1)
        response = get('/oauth/access_token', {'client_id':APP_ID,
                                               'redirect_uri':REDIRECT_URI,
                                               'client_secret':APP_SECRET,
                                               'code':code})
        ACCESS_TOKEN = urlparse.parse_qs(response)['access_token'][0]
        open(LOCAL_FILE,'w').write(ACCESS_TOKEN)
        self.wfile.write("You have successfully logged in to facebook. "
                         "You can close this window now.")

def print_status(item, color=u'\033[1;35m'):
    print color+STATUS_TEMPLATE.format(name=item['from']['name'],
                                       message=item['message'].strip())

if __name__ == '__main__':
    if not os.path.exists(LOCAL_FILE):
        print "Logging you in to facebook..."
        webbrowser.open(get_url('/oauth/authorize',
                                {'client_id':APP_ID,
                                 'redirect_uri':REDIRECT_URI,
                                 'scope':'read_stream'}))

        httpd = BaseHTTPServer.HTTPServer(('127.0.0.1', 8080), RequestHandler)
        while ACCESS_TOKEN is None:
            httpd.handle_request()
    else:
        ACCESS_TOKEN = open(LOCAL_FILE).read()
    for item in json.loads(get('/me/feed'))['data']:
        if item['type'] == 'status':
            print_status(item)
            if 'comments' in item:
                for comment in item['comments']['data']:
                    print_status(comment, color=u'\033[1;33m')
            print '---'