library/HTMLPurifier/ConfigDef.php

   1 <?php
   2
   3 /**
   4  * Configuration definition, defines directives and their defaults.
   5  * @todo Build documentation generation capabilities.
   6  */
   7 class HTMLPurifier_ConfigDef {
   8
   9     /**
  10      * Currently defined directives (and namespaces).
  11      * @note This shares the exact same structure as HTMLPurifier_Config::$conf
  12      */
  13     var $info = array();
  14
  15     /**
  16      * Initializes the default namespaces.
  17      */
  18     function initialize() {
  19         $this->defineNamespace('Core', 'Core features that are always available.');
  20         $this->defineNamespace('Attr', 'Features regarding attribute validation.');
  21         $this->defineNamespace('URI', 'Features regarding Uniform Resource Identifiers.');
  22     }
  23
  24     /**
  25      * Retrieves an instance of the application-wide configuration definition.
  26      */
  27     function &instance($prototype = null) {
  28         static $instance;
  29         if ($prototype !== null) {
  30             $instance = $prototype;
  31         } elseif ($instance === null || $prototype === true) {
  32             $instance = new HTMLPurifier_ConfigDef();
  33             $instance->initialize();
  34         }
  35         return $instance;
  36     }
  37
  38     /**
  39      * Defines a directive for configuration
  40      * @warning Will fail of directive's namespace is defined
  41      * @todo Collect information on description and allow redefinition
  42      *       so that multiple files can register a dependency on a
  43      *       configuration directive.
  44      * @param $namespace Namespace the directive is in
  45      * @param $name Key of directive
  46      * @param $default Default value of directive
  47      * @param $description Description of directive for documentation
  48      */
  49     function define($namespace, $name, $default, $description) {
  50         $def =& HTMLPurifier_ConfigDef::instance();
  51         if (!isset($def->info[$namespace])) {
  52             trigger_error('Cannot define directive for undefined namespace',
  53                 E_USER_ERROR);
  54             return;
  55         }
  56         if (isset($def->info[$namespace][$name])) {
  57             // this behavior is at risk of change
  58             trigger_error('Cannot redefine directive', E_USER_ERROR);
  59             return;
  60         }
  61         $def->info[$namespace][$name] = $default;
  62     }
  63
  64     /**
  65      * Defines a namespace for directives to be put into.
  66      * @param $namespace Namespace's name
  67      * @param $description Description of the namespace
  68      */
  69     function defineNamespace($namespace, $description) {
  70         $def =& HTMLPurifier_ConfigDef::instance();
  71         if (isset($def->info[$namespace])) {
  72             trigger_error('Cannot redefine namespace', E_USER_ERROR);
  73             return;
  74         }
  75         $def->info[$namespace] = array();
  76     }
  77
  78 }
  79
  80 ?>