In my last entry I covered how to integrate facebook api with ruby on rails using fb_graph gem. There is one problem with integrating the facebook api with your website however, and that is if facebook goes down, then your site also crashes. Yesterday facebook went down, along with the graph.facebook.com api. As a result, one of the sites I was managing went down since it kept waiting to authenticate with the facebook graph api. Now there are definitely other solutions around this, but I also found that when using facebook integration on websites, the websites load a little slower because it has to connect to facebook first, fetch the data, then render the webpage, so the performance of the webpage will heavily depend on the speed of the facebook fetch. Thus, I decided to implement a caching scheme that synchronizes a local database with information fetched from facebook. This way my page only needs to access a local database every time it’s queried, but the database is synced with facebook information, so it’s pretty much like I’m accessing facebook!!

The basic idea is as follows:

1. Create a table that stores the information you want from facebook
2. Setup a ruby script that uses the fb_graph gem calls to update the database
3. Setup that ruby script as a cron job on the webserver and run it as frequent as you like
4. Change your fb_gem calls to local database calls
5. Sit back and let the webserver do the hard work!

(09/25/10) Edit: A working version of this source code is uploaded here. Download it and follow the README to try it out!

While working on our church website, integrating with our church’s facebook fan page became a desired feature so our site maintenance team can just add an event on facebook and have it synced up to our website.

After learning about the facebook graph api, I was planning to write a library for ruby that sent out the queries and parsed the results to display on our site. However, I found the fb_graph gem written by Nov Matake and decided to try it out. The experience was extremely positive and Nov was very helpful and prompt in responding to my emails. Here’s how I integrated the facebook graph api into a ruby on rails app: