Log.php
function attach(&$observer)
    {
        if (!is_a($observer, 'Log_observer')) {
            return false;
        }

        $this->_listeners[$observer->_id] = &$observer;

        return true;
    }
function attach(&$observer)
    {
        if (!is_a($observer, 'Log_observer')) {
            return false;
        }

        $this->_listeners[$observer->_id] = &$observer;

        return true;
    }
function attach ( & $ observer ) { if ( ! is_a ( $ observer , 'Log_observer' ) ) { return false ; } $ this -> _listeners [ $ observer -> _id ] = & $ observer ; return true ; }
Adds a Log_observer instance to the list of observers that are listening
for messages emitted by this Log instance.

@param object    $observer   The Log_observer instance to attach as a
listener.

@return boolean  True if the observer is successfully attached.

@access  public
@since   Log 1.0
Adds a Log_observer instance to the list of observers that are listening for messages emitted by this Log instance .