Log in with your preferred identity on the web
If you are active and comment much on articles, blogs etc, the problem is to appear with one single identity. Lately both Facebook and Google has launched technologies (among others like MySpace)  that enables us to take our identity with us around the web for all sites implementing this functionality. This is a great step forward for social data portability.  My blog now supports both Facebook Connect and Google Friend Connect. What does this mean? First of all this means that you have the ability to log in to my site with your preferred identity. This could be Facebook account, Google account, OpenID account, Yahoo account, or AIM account. If you leave a comment on one of my post you will be identified with this account.  Her is a great video from the guys at Facebook showing how to implement Facebook Connect on your blog or site.

Critical mass
For me as a user it is great to be able to hook my identity (for example my OpenID account) on to websites where I leave a comment. The ability to log in to a new site or register as a new user and only use a button like Facebook Connect is fantastic. It is easy, convenient and lays the foundation for new social services. TripAdvisor did not manage to success with their restaurant reviews until they hooked up with Facebook. The problem for them relates to critical mass. They created a Facebook Application (LocalPick) and experienced a tremendous success

What is the long term implications?
If we look beyond blogs all sites that utilizes user generated content like reviews, ratings and so forth should be able to make use of the ongoing social data portability trend. In fact this trend should be perfect in the critical mass perspective. When I look at TripAdvisor today, they have not yet implemented the ability for users to log in with their preferred identity and use that ID to interact with the site.

For the companies that wins the battle over your identity this should give enormous opportunities. Who will win this race? Facebook, Google, MySpace? I don’t know. Imagine that on 90% of all sites (blogs, magazines, news, classifieds…) all the user generated content, like reviews, ratings, comments or listings comes through Facebook or Googles identity. This should give them a possibility to among other things further develop their ad-systems. They may utilize all the information and statistics that the users give them through their use of the web! Here is a great article at TechCrunch that reflects some of this thoughts.

Remark about Google Friend Connect
At the end; Just one reflection about the Google Friend Connect. If you are logged in to your Google account and try the friend connect on a site, you will not be given the possibility to choose other accounts. Log out of your Google account first and try the join button and see the difference.

See also: Reflections after having implemented Facebook Connect and Google Friend Connect on my blog

First of all my goal was to use an existing web application, write a facebook integration module that communicates with the Facebook APIs, extracting some information/data and presenting them inside the existing web application. The web application I used is based on a j2ee framework (jsp, java). The architecture is much like Struts The first thing to do was to get the Developer Application to my existing Facebook account. Then I had to download the Client Library. I choosed the Java Library since my development environment was Java. When I extracted the Client Library, only the source files where included. So what I had to do first (besides looking into the source code), was to compile the java-files. I actually wrote an ant-task for this purpose, but a more easier way is just to use javac without using ant-framework. The next step was to take the output from the compile process and put it into an archived file (.jar). This is not necessary but I like to do it this way and the facebook.jar file I now had is easily dropped into my existing web application library. In my Facebook profile I had to create (set up) a new application. This is done by clicking the developer application that was installed earlier. Its some steps including getting a key (API key and secret key) that I used in my java-code but this process is straight forward.

Ok, now lets start the coding process. Here is the java code controlling the session and authentication:

String apiKey = “something”;
String secretKey = “something”;

FacebookRestClient frc = null;
HttpSession session = request.getSession();
String sessionKey = (String) session.getAttribute(”facebookSession”);
String token = request.getParameter(”auth_token”);

try {

if (sessionKey != null && sessionKey.length() > 0) {

frc = new FacebookRestClient(apiKey, secretKey, sessionKey);
this.doTheThing(request, response, frc);
} else if (token != null) {
frc = new FacebookRestClient(apiKey, secretKey);
session.setAttribute(”facebookSession”, sessionKey);
sessionKey = frc.auth_getSession(token);
session.setAttribute(”facebookSession”, sessionKey);
this.doTheThing(request, response, frc);

} else {
response.sendRedirect(”http://www.facebook.com/login.php?api_key=” + apiKey + “&v=1.0″);
}
} catch (FacebookException fe) {
} catch (IOException ioe) {
…

The doTheThing method is extracting the information and looks like this:

int myid = frc.users_getLoggedInUser();
EnumSet<ProfileField> fields = EnumSet.of(com.facebook.api.ProfileField.NAME, com.facebook.api.ProfileField.PIC, com.facebook.api.ProfileField.PIC_BIG, com.facebook.api.ProfileField.PIC_SMALL);
Collection<Integer> users = new ArrayList();
users.add(myid);

// Get my information
Document d = frc.users_getInfo(users, fields);
String myname = d.getElementsByTagName(”name”).item(0).getTextContent();
String mypicture = d.getElementsByTagName(”pic”).item(0).getTextContent();

// Get my friends id
Document d2 = frc.friends_get();
String s = d2.toString();
NodeList userIDNodes = d2.getElementsByTagName(”uid”);
int fcount = userIDNodes.getLength();

Collection<Integer> friends = new ArrayList<Integer>();
for (int i = 0; i < fcount; i++) {
Node node = userIDNodes.item(i);
String idText = node.getTextContent();
Integer id = Integer.valueOf(idText);
friends.add(id);
}

List l = new ArrayList();
Map m = new HashMap();
Document d3 = frc.users_getInfo(friends, fields);

// Get my friends information
for (int j = 0; j < fcount; j++) {
String name2 = d3.getElementsByTagName(”name”).item(j).getTextContent();
String picture2 = d3.getElementsByTagName(”pic”).item(j).getTextContent();
String picture3 = d3.getElementsByTagName(”pic_small”).item(j).getTextContent();
String picture4 = d3.getElementsByTagName(”pic_big”).item(j).getTextContent();

m.put(”name”, name2);
m.put(”picture”, picture2);
m.put(”picture_small”, picture3);
m.put(”picture_big”, picture4);

l .add(m);
m = new HashMap();

}
request.setAttribute(”friends”, l);
request.setAttribute(”myname”, myname);
request.setAttribute(”mypicture”, mypicture);
request.setAttribute(”numFriends”, new Integer(fcount));

So all the information from Facebook is now added to the request and can be displayed in a JSP. The code above is not very elegant and is not optimized(!). Its just a pice of code done after half an hour of work and my goal was to implement an integration module for testing purpose.

Hope this blog post can help others looking for hints when getting started with Facebook application development/integration.