library/HTMLPurifier/URIFilter.php

   1 <?php
   2
   3 /**
   4  * Chainable filters for custom URI processing.
   5  *
   6  * These filters can perform custom actions on a URI filter object,
   7  * including transformation or blacklisting.  A filter named Foo
   8  * must have a corresponding configuration directive %URI.Foo,
   9  * unless always_load is specified to be true.
  10  *
  11  * The following contexts may be available while URIFilters are being
  12  * processed:
  13  *
  14  *      - EmbeddedURI: true if URI is an embedded resource that will
  15  *        be loaded automatically on page load
  16  *      - CurrentToken: a reference to the token that is currently
  17  *        being processed
  18  *      - CurrentAttr: the name of the attribute that is currently being
  19  *        processed
  20  *      - CurrentCSSProperty: the name of the CSS property that is
  21  *        currently being processed (if applicable)
  22  *
  23  * @warning This filter is called before scheme object validation occurs.
  24  *          Make sure, if you require a specific scheme object, you
  25  *          you check that it exists. This allows filters to convert
  26  *          proprietary URI schemes into regular ones.
  27  */
  28 abstract class HTMLPurifier_URIFilter
  29 {
  30
  31     /**
  32      * Unique identifier of filter
  33      */
  34     public $name;
  35
  36     /**
  37      * True if this filter should be run after scheme validation.
  38      */
  39     public $post = false;
  40
  41     /**
  42      * True if this filter should always be loaded (this permits
  43      * a filter to be named Foo without the corresponding %URI.Foo
  44      * directive existing.)
  45      */
  46     public $always_load = false;
  47
  48     /**
  49      * Performs initialization for the filter.  If the filter returns
  50      * false, this means that it shouldn't be considered active.
  51      */
  52     public function prepare($config) {return true;}
  53
  54     /**
  55      * Filter a URI object
  56      * @param $uri Reference to URI object variable
  57      * @param $config Instance of HTMLPurifier_Config
  58      * @param $context Instance of HTMLPurifier_Context
  59      * @return bool Whether or not to continue processing: false indicates
  60      *         URL is no good, true indicates continue processing. Note that
  61      *         all changes are committed directly on the URI object
  62      */
  63     abstract public function filter(&$uri, $config, $context);
  64
  65 }
  66
  67 // vim: et sw=4 sts=4