Frankie Goes To Facebook

UPDATED 4/12/2008: Now compatible with Sinatra 0.2.0
So you want to create a small Facebook application... seems like it should be a small thing, right? But creating an entire Ruby on Rails application just for a tiny little Facebook application is, at the very least, a bit wasteful. In the case of a overly popular Facebook app you could end up with, as Marc Andreessen put it, a "self-inflicted denial of service attack", unless you have both a pretty serious infrastructure to support it, as well as lots of cash to keep that data center running.

Wouldn't you rather be able to create a highly scalable "hello, world" Facebook application in around 13 lines of Ruby code? Say hello to Frankie:

require 'rubygems'
require 'frankie'

configure do
  set_option :sessions, true
  load_facebook_config "./config/facebooker.yml", Sinatra.env
end

## facebooker helpers
before do
  ensure_authenticated_to_facebook
  ensure_application_is_installed_by_facebook_user
end

## the site
get '/' do
  body "<h1>Hello #{session['facebook_session'].user.name} and welcome to frankie!</h1>"
end

Frankie is a plugin for the minimalist and very fast Sinatra web framework that allows you to easily create a Facebook application by using the Facebooker gem. Why would you want to use it? If your Facebook application needs to be highly scalable, is fairly small, or is really a mashup of other web-available resources, than Frankie could be a good solution.

Frankie is available now for your enjoyment. Here is how to get started:

- Install the Frankie gem, which will install the Sinatra and Facebooker gems if you do not already have them.

sudo gem install frankie

- Create the application directories for your new app:

mkdir myapp
cd myapp
mkdir config

- Put your facebooker.yml file into the /myapp/config directory, and set the values to your information. Here is a simple example of the file:

-------
development:
 api_key: apikeyhere 
 secret_key: secretkeyhere
 canvas_page_name: yourcanvashere    
 callback_url: http://localhost:4567
test:
 api_key: apikeyhere 
 secret_key: secretkeyhere
 canvas_page_name: yourcanvashere    
 callback_url: http://localhost:4567
production:
 api_key: apikeyhere 
 secret_key: secretkeyhere
 canvas_page_name: yourcanvashere    
 callback_url: http://yourrealserver.com

- Make sure you have setup your facebook application on the facebook site. Google "setup new facebook application" if you are unsure how to do this. I recommend starting with an IFrame application, so that you can point a development version of your Facebook application to your local machine. This, like our example here, would use "http://localhost:4567" as the callback URL when configuring the Facebook app.

- Create your application, based on the sample above, and run it:

ruby sample.rb

This will start the Sinatra Ruby web server running:

== Sinatra has taken the stage on port 4567!

- Test it by pointing your browser to http://apps.facebook.com/yourappname. If you have things setup correctly then you should see your application appear inside of Facebook's site.

Facebook is now your playground... have fun with Frankie!