title: Getting a user access token in facebook using Koala
body: <p>I am writing a simple procedure that automatically makes a facebook
  post. From what I understand, I need to have a "user access token" to
  do this. I am using Koala (but the philosophy is similar for other
  libraries). Anyway, I create a new OAuth account:</p>
  
  <pre><code>@oauth = Koala::Facebook::OAuth.new(app_id, app_secret, callback_url)
  </code></pre>
  
  <p>The koala instructions then become somewhat unclear. The next two lines are:</p>
  
  <pre><code>@oauth.url_for_oauth_code # generate authenticating URL
  @oauth.get_access_token(code) # fetch the access token once you have the code
  </code></pre>
  
  <p>Where does the "code" variable come from? It doesn't say in the
  documentation. Also, does the "get_access_token" method get an "app
  access token" or a "user_access_token"? The method name is not clear.
  I tried going to the url that the [url_for_oauth_code] method gave me,
  but it gives me no code! Where does the "code" variable come from?</p>