Facebook + Drupal
Let's face it, OpenID has failed and is being less and less supported. Four years ago, I wrote a promising post about OpenID, but at that time I probably didn't even had a Facebook account. Now it's 2011 and Facebook is silently becoming the main identity provider in our part of the world.
Remember that amazing presentation by Dick Hardt (yes that's his real name) back in 2005 about idenity 2.0? Our internet passport? If not check it out below, and most notably check out the possible solutions he saw for the future (around 13:00). Facebook was still a startup and Twitter didn't even exist.
I don't know whether this is all a Good Thing or that it's the start an almighty big brother called Facebook and the End Of All Privacy. It's an interesting discussion and you can find a lot of discussion about that on the net. But Facebook connect does offer a lot of opportunities for site builders to connect with their audience. Who knows, maybe something like diaspora will offer us all a more decentralized way to store our identity, but I'm not holding my breath for that to happen.
Connecting Drupal with Facebook
There are almost a dozen Facebook related modules for Drupal. Most of them leverage the social plugins Facebook offers and some of them just imitate some kind of Facebook functionality. Here is an overview:
Allows your visitors to connect/register with your Drupal site using their Facebook credentials. It relies on the Facebook PHP Software Development Kit (SDK) and your theme being Facebook Markup Language (FMBL) ready. In order to make it work, you will need to create a Facebook App. The user credentials are given to the app and you connect with the app through Drupal.
This module also provides a connect option, but it also does a lot more. In fact, it allows you to show you whole site with all functionality in a facebook App. Effictively transforming your Drupal site into a Facebook App. See the demo site/app for more info.
Facebook uses Oauth 2.0 (just like Twitter) and the whole authentication concept is explained in detail here.
Social modules (like / share)
Facebook prefers you use their Like button they launched last year instead of the share functionality. But you can (still) use both. The effect is different!
By the way, ever noticed how Facebook tries to figure out which image to show as a thumbnail preview next to your shared link? Take a look at this article if you want to have influence on which image this should be.
Below modules do not connect with FB but they offer ways to mimic some functionality like the Wall posts.
Looking for more Drupal + Facebook stuff? Check out the Facebook API group on d.o