gistfile1.php

<?php

class FieldChangeHook
{
    protected static $fetchedRow = array();
    
    /**
     * Called as before_save logic hook to grab the fetched_row values
     */
    public function saveFetchedRow($bean, $event, $arguments)
    {
        if ( !empty($bean->id) ) {
            self::$fetchedRow[$bean->id] = $bean->fetched_row;
        }
    }
    
    /**
     * Called as a after_save logic hook to execute the actual business process
     */
    public function executeBusinessProcess($bean, $event, $arguments)
    {
        // call on changed records only
        if ( isset(self::$fetchedRow[$bean->id]) && $this->fieldname != self::$fetchedRow[$bean->id]['fieldname'] ) {
            //
            // execute changed record business process
            //
        }
        
        // call on new records only
        if ( !isset(self::$fetchedRow[$bean->id]) ) {
            //
            // execute new record business process
            //
        }
    }
}