To begin, a little history lesson is needed. Many users do not like having to register for each blog where they would like to post comments, especially if they already have accounts on so many other social networks, such as Facebook and MySpace. So a single online ID for several purposes would be ideal, wouldn’t it? That’s the idea behind the OpenID protocol, which started in 2005. It decentralizes the identification of users for various providers and services. In essence, you can create an account on Facebook and connect it to services such as MySpace or even a personal blog. If you want to change your profile for all of these services, that too is decentralized: you simply change the settings on your Facebook account. OpenID is a chance to make the Web and its services more easily accessible. There are reasonable risks and concerns involved, but also many opportunities.
Facebook announced in 2007 that it would implement OpenID, and others followed, which explains why we now find more and more buttons that say “Connect with Facebook” or “Google Friend Connect.” This leads us to our second plug-in, Facebook Connect WordPress plug-in, which almost seamlessly integrates Facebook into your blog.
The plug-in allows users to comment on a blog using their Facebook account; and if they are already signed in or on Facebook, they need not sign in again. Users do not have to register for a unique account on the blog because the plug-in retrieves the user’s information directly from the Facebook API. With access to the user profiles on Facebook, you can display your users’ profile pictures, which adds a personal touch to your blog.
The plug-in integrates a lot of Facebook functions: for example, users can send invitations and share stories and comments on Facebook, which gives your blog the benefit of word-of-mouth marketing. To do this, you need to activate the plug-in option that publishes a user’s activity in their respective activity feed. Last but not least, you can enable a gadget that displays the profile pictures of your blog’s most recent visitors, similar to “Google Friend Connect.”
This plug-in essentially does the opposite of Wordbook (which integrates Facebook functionality into your blog).
Plug-In Installation and Configuration
Again, as in the previous section, you will need to create a new Facebook application.
Creating a new Facebook application. Large view.
You will also have to define the callback URLs, which point to the root of your blog.
Defining callback URLs for the new application. Large view.
Again, most of the work is now done, and you can soon start having fun and being creative. Just a few steps remain. First, download the plug-in from the website (see link above) and upload and enable it. A big part of the plug-in consists of the “Facebook Connect” library, which is provided by Facebook. You might stumble over the two xd_reciever files, one in HTML and one in PHP. They play a key role: enabling the so-called cross-domain communication (hence, the xd) between your blog and Facebook.
So why are these needed? Typically, HTTP requests are sent with the XMLHttpRequest object. However, the typical security settings on browsers allow XMLHttpRequest to send requests only to the domain where the original request was sent to. In our case, requests are send to and from Facebook. This cross-domain communication is achieved with iFrame cross-domain communication. With this, the application opens an iFrame on facebook.com with the relevant requests; for example, to retrieve information on whether a user is logged into Facebook.
These requests are sent to Facebook through the iFrame via the URL, with which the iFrame is opened. The request is checked, and now the Facebook script that was called via the iFrame opens an iFrame on the application page, where the outcome of the request is sent to, again with the query string of the URL. The result of any requests lands in the query string of the xd_receiver.htm file on your own server. This circumvents the problem of being unable to use XMLHttpRequest.
Now back to the plug-in. Once you have installed and activated the plug-in, you can add the plug-in as a widget to your blog’s sidebar. However, you first need to enter your API key and secret.
Settings for Facebook Connect WordPress plug-in. Large view.
As you will see, a whole lot of options are enabled by default, such as automatically publishing comments if they are posted through a Facebook account (the rationale being that you don’t have to moderate them because they come from actual people using Facebook and not spambots).
If you activate the sharing function, the plug-in adds a “Share” button automatically below each post. You can also activate the option that publishes a user’s comments in their activity feed on Facebook, thus making their activity on your blog visible to their friends.
After you have adjusted the settings, you will be notified that you need to define templates for the presentation. These need to be “synchronized” with Facebook. Scroll down a bit to generate and activate these templates. You can change the language manually here as well.
Adjust Facebook Connect’s template settings. Large view.
The first template controls how a user’s activity is posted in their activity feed on Facebook. However, you can also include the activity feed of your users in your gadget, as done on sociable.es (see link above). The last step is to go to the widget set-up page and include the gadget as a widget in your sidebar.
Here again, you have some choice over the configuration, especially with regard to changing the language, showing a big or small “Connect to Facebook” button, etc. After installing the plug-in, you may want to see what else you can do with it. The implementation on sociable.es is quite a nice one.