title: Facebook Application Using CodeIgniter
body: <p>I am building a Facebook app using iframe rendering. I want to use CodeIgniter for the back end and am wondering what all the settings should be set to for CodeIgniter and Facebook to get along. Specific settings I am wondering about are:</p>
  
  <ol>
  <li>Facebook's canvas callback url (should it include the default controller and function)?</li>
  <li>config.php's base_url, index_page, uri_protocol, enable_query_strings</li>
  <li>Anything else I might be missing</li>
  </ol>
  
  <p>How I have the Facebook interaction set up currently is creating a new controller FB_Controller that is added to the libraries folder that every one of my controllers inherit from. FB_Controller inherits from Controller and has a property $facebook that is instantiated using the API key and secret upon construction. Not sure if this the best approach.</p>
  
  <p>I am also using mod_rewrite to get rid of index.php and just so there's no confusion here's the code:</p>
  
  <pre><code>&lt;IfModule mod_rewrite.c&gt;
      RewriteEngine On
      RewriteBase /
  
      RewriteCond %{REQUEST_URI} ^system.*
      RewriteRule ^(.*)$ /index.php?/$1 [L]
  
      RewriteCond %{REQUEST_FILENAME} !-f
      RewriteCond %{REQUEST_FILENAME} !-d
      RewriteRule ^(.*)$ index.php?/$1 [L]
  &lt;/IfModule&gt;
  </code></pre>