library/HTMLPurifier/Context.php

   1 <?php
   2
   3 /**
   4  * Registry object that contains information about the current context.
   5  * @warning Is a bit buggy when variables are set to null: it thinks
   6  *          they don't exist! So use false instead, please.
   7  */
   8 class HTMLPurifier_Context
   9 {
  10
  11     /**
  12      * Private array that stores the references.
  13      * @private
  14      */
  15     var $_storage = array();
  16
  17     /**
  18      * Registers a variable into the context.
  19      * @param $name String name
  20      * @param $ref Variable to be registered
  21      */
  22     function register($name, &$ref) {
  23         if (isset($this->_storage[$name])) {
  24             trigger_error("Name $name produces collision, cannot re-register",
  25                           E_USER_ERROR);
  26             return;
  27         }
  28         $this->_storage[$name] =& $ref;
  29     }
  30
  31     /**
  32      * Retrieves a variable reference from the context.
  33      * @param $name String name
  34      * @param $ignore_error Boolean whether or not to ignore error
  35      */
  36     function &get($name, $ignore_error = false) {
  37         if (!isset($this->_storage[$name])) {
  38             if (!$ignore_error) {
  39                 trigger_error("Attempted to retrieve non-existent variable $name",
  40                               E_USER_ERROR);
  41             }
  42             $var = null; // so we can return by reference
  43             return $var;
  44         }
  45         return $this->_storage[$name];
  46     }
  47
  48     /**
  49      * Destorys a variable in the context.
  50      * @param $name String name
  51      */
  52     function destroy($name) {
  53         if (!isset($this->_storage[$name])) {
  54             trigger_error("Attempted to destroy non-existent variable $name",
  55                           E_USER_ERROR);
  56             return;
  57         }
  58         unset($this->_storage[$name]);
  59     }
  60
  61     /**
  62      * Checks whether or not the variable exists.
  63      * @param $name String name
  64      */
  65     function exists($name) {
  66         return isset($this->_storage[$name]);
  67     }
  68
  69     /**
  70      * Loads a series of variables from an associative array
  71      * @param $context_array Assoc array of variables to load
  72      */
  73     function loadArray(&$context_array) {
  74         foreach ($context_array as $key => $discard) {
  75             $this->register($key, $context_array[$key]);
  76         }
  77     }
  78
  79 }
  80