def get_app_access_token
      return connection_params[:app_access_token] if connection_params.has_key? :app_access_token

      @oauth = Koala::Facebook::OAuth.new(connection_params[:app_id], connection_params[:app_secret], callback_url)
      connection_params[:app_access_token] = @oauth.get_app_access_token
    end
def get_app_access_token
      return connection_params[:app_access_token] if connection_params.has_key? :app_access_token

      @oauth = Koala::Facebook::OAuth.new(connection_params[:app_id], connection_params[:app_secret], callback_url)
      connection_params[:app_access_token] = @oauth.get_app_access_token
    end
A long-term app_access_token might be supplied on connection parameters
 If not, we fetch a short-term one here.