<?php
// $Id: observer.php,v 1.1 2003/04/23 03:52:29 vieglais Exp $
// $Horde: horde/lib/Log/observer.php,v 1.5 2000/06/28 21:36:13 jon Exp $

/**
 * The Log_observer:: class implements the Observer end of a
 * Subject-Observer pattern for watching log activity and taking
 * actions on exceptional events.
 *
 * @author  Chuck Hagenbuch <chuck@horde.org>
 * @version $Revision: 1.1 $
 * @since   Horde 1.3
 * @package Log
 */
class Log_observer {
 
    /** 
    * The minimum priority level of message that we want to hear
    * about. PEAR_LOG_EMERG is the highest priority, so we will only
    * hear messages with an integer priority value less than or
    * equal to ours. It defaults to PEAR_LOG_INFO, which listens to
    * everything except PEAR_LOG_DEBUG. 
    * @var string
    */
    var $_priority = PEAR_LOG_INFO;


    /**
     * Basic Log_observer instance that just prints out messages
     * received.
     * @param string $priority priority level of message
     * @access public
     */
    function Log_observer($priority = PEAR_LOG_INFO)
    {
        $this->_priority = $priority;
    }

    /**
     * Attempts to return a concrete Log_observer instance of the
     * specified type.
     * 
     * @param string $observer_type  The type of concrate Log_observer subclass
     *                          to return.  We will attempt to dynamically
     *                          include the code for this subclass.
     * @param string $priority priority level of message
     * @return object Log_observer  The newly created concrete Log_observer
     * instance, or an false on an error.
     */
    function factory($observer_type, $priority = PEAR_LOG_INFO)
    {
        $classfile = substr(__FILE__, 0, -(strlen(basename(__FILE__)))) . 'Log/' . $observer_type . '.php';
        if (file_exists($classfile)) {
            include_once $classfile;
            $class = 'Log_' . $observer_type;
            return new $observer_type($priority);
        } else {
            return false;
        }
    }

    /**
     * This is a stub method to make sure that LogObserver classes do
     * something when they are notified of a message. The default
     * behavior is to just print the message, which is obviously not
     * desireable in practically any situation - which is why you need
     * to override this method. :)
     * 
     * @param array $messageOb    A hash containing all information - the text
     *                      message itself, the priority, what log it came
     *                      from, etc.
     */
    function notify($messageOb)
    {
        print_r($messageOb);
    }
}

?>
