library/HTMLPurifier/Filter.php

   1 <?php
   2
   3 /**
   4  * Represents a pre or post processing filter on HTML Purifier's output
   5  *
   6  * Sometimes, a little ad-hoc fixing of HTML has to be done before
   7  * it gets sent through HTML Purifier: you can use filters to acheive
   8  * this effect. For instance, YouTube videos can be preserved using
   9  * this manner. You could have used a decorator for this task, but
  10  * PHP's support for them is not terribly robust, so we're going
  11  * to just loop through the filters.
  12  *
  13  * Filters should be exited first in, last out. If there are three filters,
  14  * named 1, 2 and 3, the order of execution should go 1->preFilter,
  15  * 2->preFilter, 3->preFilter, purify, 3->postFilter, 2->postFilter,
  16  * 1->postFilter.
  17  *
  18  * @note Methods are not declared abstract as it is perfectly legitimate
  19  *       for an implementation not to want anything to happen on a step
  20  */
  21
  22 class HTMLPurifier_Filter
  23 {
  24
  25     /**
  26      * Name of the filter for identification purposes.
  27      * @type string
  28      */
  29     public $name;
  30
  31     /**
  32      * Pre-processor function, handles HTML before HTML Purifier
  33      * @param string $html
  34      * @param HTMLPurifier_Config $config
  35      * @param HTMLPurifier_Context $context
  36      * @return string
  37      */
  38     public function preFilter($html, $config, $context)
  39     {
  40         return $html;
  41     }
  42
  43     /**
  44      * Post-processor function, handles HTML after HTML Purifier
  45      * @param string $html
  46      * @param HTMLPurifier_Config $config
  47      * @param HTMLPurifier_Context $context
  48      * @return string
  49      */
  50     public function postFilter($html, $config, $context)
  51     {
  52         return $html;
  53     }
  54 }
  55
  56 // vim: et sw=4 sts=4