<?php

/**
 * Represents a pre or post processing filter on HTML Purifier's output
 * 
 * Sometimes, a little ad-hoc fixing of HTML has to be done before
 * it gets sent through HTML Purifier: you can use filters to acheive
 * this effect. For instance, YouTube videos can be preserved using
 * this manner. You could have used a decorator for this task, but
 * PHP's support for them is not terribly robust, so we're going
 * to just loop through the filters.
 * 
 * Filters should be exited first in, last out. If there are three filters,
 * named 1, 2 and 3, the order of execution should go 1->preFilter,
 * 2->preFilter, 3->preFilter, purify, 3->postFilter, 2->postFilter,
 * 1->postFilter.
 */

class HTMLPurifier_Filter
{
    
    /**
     * Name of the filter for identification purposes
     */
    var $name;
    
    /**
     * Pre-processor function, handles HTML before HTML Purifier 
     */
    function preFilter($html, $config, &$context) {}
    
    /**
     * Post-processor function, handles HTML after HTML Purifier
     */
    function postFilter($html, $config, &$context) {}
    
}