library/HTMLPurifier/AttrTransform.php

   1 <?php
   2
   3 /**
   4  * Processes an entire attribute array for corrections needing multiple values.
   5  *
   6  * Occasionally, a certain attribute will need to be removed and popped onto
   7  * another value.  Instead of creating a complex return syntax for
   8  * HTMLPurifier_AttrDef, we just pass the whole attribute array to a
   9  * specialized object and have that do the special work.  That is the
  10  * family of HTMLPurifier_AttrTransform.
  11  *
  12  * An attribute transformation can be assigned to run before or after
  13  * HTMLPurifier_AttrDef validation.  See HTMLPurifier_HTMLDefinition for
  14  * more details.
  15  */
  16
  17 abstract class HTMLPurifier_AttrTransform
  18 {
  19
  20     /**
  21      * Abstract: makes changes to the attributes dependent on multiple values.
  22      *
  23      * @param $attr Assoc array of attributes, usually from
  24      *              HTMLPurifier_Token_Tag::$attr
  25      * @param $config Mandatory HTMLPurifier_Config object.
  26      * @param $context Mandatory HTMLPurifier_Context object
  27      * @returns Processed attribute array.
  28      */
  29     abstract public function transform($attr, $config, $context);
  30
  31     /**
  32      * Prepends CSS properties to the style attribute, creating the
  33      * attribute if it doesn't exist.
  34      * @param $attr Attribute array to process (passed by reference)
  35      * @param $css CSS to prepend
  36      */
  37     public function prependCSS(&$attr, $css) {
  38         $attr['style'] = isset($attr['style']) ? $attr['style'] : '';
  39         $attr['style'] = $css . $attr['style'];
  40     }
  41
  42     /**
  43      * Retrieves and removes an attribute
  44      * @param $attr Attribute array to process (passed by reference)
  45      * @param $key Key of attribute to confiscate
  46      */
  47     public function confiscateAttr(&$attr, $key) {
  48         if (!isset($attr[$key])) return null;
  49         $value = $attr[$key];
  50         unset($attr[$key]);
  51         return $value;
  52     }
  53
  54 }
  55
  56 // vim: et sw=4 sts=4