Source for file TokenCollector.abstract.php

<?php
/**
 * @package harmoni.osid_v2.authentication
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: TokenCollector.abstract.php,v 1.2 2005/03/23 21:26:40 adamfranco Exp $
 */ 
 
/**
 * The TokenCollector is reponsible for prompting a user authentication tokens
 * and recieving the response from the user.
 * 
 * @package harmoni.osid_v2.authentication
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: TokenCollector.abstract.php,v 1.2 2005/03/23 21:26:40 adamfranco Exp $
 */
class TokenCollector {
    
    /**
     * Run the token collection sequence involving prompting for and collecting
     * tokens.
     * 
     * @return mixed 
     * @access public
     * @since 3/18/05
     */
    function collectTokens () {
        if (!$tokens = $this->collect()) {
            $this->prompt();
            $tokens = $this->collect();
        }
        
        return $tokens;
    }
        
    /**
     * Prompt the user to supply their tokens
     * 
     * @return void 
     * @access public
     * @since 3/16/05
     */
    function prompt () {
         die ("Method <b>".__FUNCTION__."()</b> declared in interface<b> ".__CLASS__."</b> has not been overloaded in a child class."); 
    }
    
    /**
     * Collect any tokens that the user may have supplied. Reply NULL if none
     * are found.
     * 
     * @return mixed 
     * @access public
     * @since 3/16/05
     */
    function collect () {
         die ("Method <b>".__FUNCTION__."()</b> declared in interface<b> ".__CLASS__."</b> has not been overloaded in a child class."); 
    }
}
 
?>