clear facebook session

Handle Facebook session expiry with Facebooker

Facebooker is the most commonly used ruby interface to the Facebook API. It is considered stable and generally is being kept up to date with the frequent-and-annoying Facebook API changes.

Facebook has some strict rules you have to consider when using their API and FacebookConnect integration, onehidden rule for example, says something like that:

“If you use Facebook Connect on your site, the cookie that we are going to use, is the same cookie we keep for our main site,
Facebook.com”

Meaning basically that if a user is connected to your application (via Connect or through FBML, doesn’t really matter if it’s FBML) and he or she logs out of the main facebook site, they will also log out from the Facebook session on your application. Basically saying, that the user’s facebook session in your application, can be reseted without an explicit action from the user on your site. epic win facebook.

In order to handle that kind of situation you’ll have to rescue the Facebooker::Session::SessionExpired and use the failsafe Rails method named rescue_from:

ApplicationController < ActionController::Base

  rescue_from Facebooker::Session::SessionExpired, :with => :facebook_session_expired


  protected

  def facebook_session_expired
    clear_fb_cookies!
    clear_facebook_session_information
    reset_session # remove your cookies!
    flash[:error] = "Your facebook session has expired."
    redirect_to root_url
  end

end

view rawapplication.rbThis Gist brought to you by GitHub.

This will clear up all the Facebook remnants in your user’s session and will force him to reload.

Note that if the user granted you with the “offline access” permission and you saved the credentials, you will be able to restore the session without notifying the user.

http://stackoverflow.com/questions/894446/destroy-cookies-in-rails-facebook-connect-facebooker-plugin