This is a follow-up to one of my most popular posts, “Getting a Facebook Login working with your application“. That was written in 2007, and is quite out of date.

This entire post was inspired by a reader who e-mailed me asking for help. I’m more than happy to help someone who is learning. It makes the whole thing worthwhile.

In May 2008, Facebook announced “Facebook Connect”, a Trusted authentication method so that user’s profiles can be used on other sites. My 2007 article pretty much does what Facebook Connect does for you now, but Facebook have made it much easier. To get started, take a look at the Facebook Connect web pages and more specifically, the single sign-on guide.

A few things of note:

1. This does not replace your current login system. You still need a user database
2. People still need to click “connect” and you cannot use general session/cookie information to simply log in without interaction.

Facebook claims it gives you 15% more registrations, so what are you waiting for, get started!

If you liked this, you may also like:

1. Getting a Facebook Login working on your application
2. Facebook Platform – a thought
3. The Facebook Platform

Update 2010: This method is still valid but has been replaced with “Facebook Connect”. See a follow-up post: Facebook Logins with Facebook Connect

I’m writing this after a hard day’s work with the Facebook API. It’s almost been work the blood, sweat and tears that I have shed during the last 5 hours. This will also hopefully serve as a guide for anyone trying to get something simple done with facebook authentication.

Firstly, my mission:

• Enhance the current login system of USE to use Facebook, thereby giving me access to their facebook profiles and posting messages to them there, instead of giving my users ‘just another thing to update’
• At this point in time, I only want my users to be able to log in with facebook
• Doing this also makes my login more secure

My first steps take me to platform.facebook.com and to their guides. I add the developer application and get myself an API key, setting up my server at the same time. There are plenty of other tutorials that show you how to do that.

The next thing I do is go to the authenticaiton documentation and grab their login button and put it into my website. As previously mentioned in other posts, I wanted to use the thickbox technique to log in; however, I then came upon the first limitations of the facebook platform

1. The thickbox can open an iframe with the facebook login in it, but in order to close that box on the click of login, I have to attach some javascript to the button, which I can’t do
2. Even simply having the login come up in a popup has the same problem.
3. Even so, ignoring that, once you click ok, Facebook redirects you to the callback page, but it does so in the iframe/popup!
4. Even if that was all acceptable, in order to retrieve the Facebook session, you need to use the auth token provided in the returned URL, which you can’t get at in the iframe/popup without some funky javascript

Thus, I’ve dropped the thickbox login. Very sorry. If you can think of a way around this, please please please let me know.

Next comes with what to do with everything. My previous login was actually controlled by the phpBB forums and, whilst it is still possible to throw the token to the forums, I haven’t in this example as it overcomplicates things (and I’m waiting for phpBBv3 to go gold). I considered the following tasks that the script had to do before it would log people in

1. Test if the auth_token is real
2. Test if the user is in the database
3. Get their details and fill my session variables
4. Prevent this process from happening every time

The first one was quite easy actually. Looking at the facebook.php file in the client library (from the developer tools) I found a do_get_session($auth_token) method. This swaps my token for a session, returning an array if it’s alright, nothing if it’s not. The array contains the user id, session key and a time for when the session expires

The second bit is the hardest. On sheffieldhockey.com alone there are 435 registered members (though only half that number are active really). Also, not all of them are on facebook and I certainly don’t know their facebook IDs to populate the database with. Therefore, this second bit involves a test to see if the user is there, then if they’re not, they will be bounced to a page asking them to register, or to pick their name from a list. This is the only way I can see a nice smooth transition without me getting the admin to trawl facebook for people.

The third part isn’t that hard, assuming there’s a person in there. Simply get the data and set it.

Preventing it from happening each time is a simple check of the sessions to see if they’re set and then if an auth_token is set. The trickiest part of this was that I’d been defining my variables twice and so it looked like the sessions weren’t setting until a refresh of the page. Thankfully that’s fixed now.

The hardest part in this game actually seemed to be getting the logout working! Facebook requires that to log a user out you must POST to www.facebook.com/logout.php with confirm=1 set. I tried a couple of ways first, initially with a form, but that simply dropped me out into a Facebook login screen and when I went back, I hadn’t cleared my sessions so I was still logged in!

Secondly, I tried and AJAX request to the page, but that page disallowed it. Finally, I found a script that let you do POST requests without forms (google for it) and from there I made a page, called the function, cleared my sessions and headered back as normal.

And all that does is log you in… it’s a lot of work for not very much, but it’ll allow you to do so much more. That said, the pain of not being able to do the thickbox login is annoying and to be honest it distracts from the site. Any way around that and I’ll be eternally greatful!

There’s no nightly USE build tonight due to the above (and me not having finished the facebook ID associator)

Steve

Currently Listening to: My Chill playlist for Emily
Currently Reading: Facebook documentation
Currently Watching: Batman Begins
Currently Eating: Leftovers and Milka
Current SVN Revision: 81

If you liked this, you may also like:

1. Facebook Logins with Facebook Connect
2. Facebook Platform – a thought
3. Fixes and Fancy Stuff

First, sorry for not updating this blog in the past month. I’ve been to Greece and then spent another week here doing all the touristy things with my girlfriend so I’ve not really had time to update this.

I’d then like to say, that whilst I’ve not been updating this, I’ve been hard at work on USEv4. Since I last updated, the whole site has been put into the templates and at the moment I’m just going over everything and fixing any problems I come across. Whilst I’ve been doing this I’ve been getting the opportunity to add a couple of fancy bits in. For instance, I’ve now got the Thickbox jQuery plugin working for squad status (see below)

Basically, instead of popping up a new window showing the page, this tiny 10KB plugin makes the rest of the page inactive and gets whatever little bit of data I want. This will also be used in the new facebook login

Talking of the Facebook login, I’m going to try and have that done by early next week. I’m actually quite looking forward to getting on to the new stuff. Fixing the current site (all 20,000 lines of it) is alright, but it’s monotonous and really gets to me because it’s very repetitive. New stuff gives me chance to make things better, not just fighting to make them work!

So, Wanna see what this all looks like?
http://beta.steel-software.com
Username: hockey
Password: love

It’s updated nightly with the latest revision and there’s a list of things that are working and aren’t on the front page.

I’d love to hear what you think and if you find anything that’s wrong. Also, I’d love to know about how fast the website loads. At the moment the adverts are disabled so that’ll save some time, but I often worry that it’s getting a little bloated.

Anywho, that’s enough from me. Take a look at the site!

Steve

Currently Listening to: The White Stripes
Currently Eating: Chicken Rogan Josh
Currently Watching: Whose Line is it Anyway
Currently Reading: Nothing, Harry Potter was good though!
Current SVN Revision: 75

If you liked this, you may also like:

1. Getting a Facebook Login working on your application
2. Facebook Logins with Facebook Connect
3. USEv4 is Done!