File indexing completed on 2024-12-22 05:36:21

 <?php
 
 /**
  * Configuration object that triggers customizable behavior.
  *
  * @warning This class is strongly defined: that means that the class
  *          will fail if an undefined directive is retrieved or set.
  *
  * @note Many classes that could (although many times don't) use the
  *       configuration object make it a mandatory parameter.  This is
  *       because a configuration object should always be forwarded,
  *       otherwise, you run the risk of missing a parameter and then
  *       being stumped when a configuration directive doesn't work.
  *
  * @todo Reconsider some of the public member variables
  */
 class HTMLPurifier_Config
 {
 
     /**
      * HTML Purifier's version
      * @type string
      */
     public $version = '4.9.3';
 
     /**
      * Whether or not to automatically finalize
      * the object if a read operation is done.
      * @type bool
      */
     public $autoFinalize = true;
 
     // protected member variables
 
     /**
      * Namespace indexed array of serials for specific namespaces.
      * @see getSerial() for more info.
      * @type string[]
      */
     protected $serials = array();
 
     /**
      * Serial for entire configuration object.
      * @type string
      */
     protected $serial;
 
     /**
      * Parser for variables.
      * @type HTMLPurifier_VarParser_Flexible
      */
     protected $parser = null;
 
     /**
      * Reference HTMLPurifier_ConfigSchema for value checking.
      * @type HTMLPurifier_ConfigSchema
      * @note This is public for introspective purposes. Please don't
      *       abuse!
      */
     public $def;
 
     /**
      * Indexed array of definitions.
      * @type HTMLPurifier_Definition[]
      */
     protected $definitions;
 
     /**
      * Whether or not config is finalized.
      * @type bool
      */
     protected $finalized = false;
 
     /**
      * Property list containing configuration directives.
      * @type array
      */
     protected $plist;
 
     /**
      * Whether or not a set is taking place due to an alias lookup.
      * @type bool
      */
     private $aliasMode;
 
     /**
      * Set to false if you do not want line and file numbers in errors.
      * (useful when unit testing).  This will also compress some errors
      * and exceptions.
      * @type bool
      */
     public $chatty = true;
 
     /**
      * Current lock; only gets to this namespace are allowed.
      * @type string
      */
     private $lock;
 
     /**
      * Constructor
      * @param HTMLPurifier_ConfigSchema $definition ConfigSchema that defines
      * what directives are allowed.
      * @param HTMLPurifier_PropertyList $parent
      */
     public function __construct($definition, $parent = null)
     {
         $parent = $parent ? $parent : $definition->defaultPlist;
         $this->plist = new HTMLPurifier_PropertyList($parent);
         $this->def = $definition; // keep a copy around for checking
         $this->parser = new HTMLPurifier_VarParser_Flexible();
     }
 
     /**
      * Convenience constructor that creates a config object based on a mixed var
      * @param mixed $config Variable that defines the state of the config
      *                      object. Can be: a HTMLPurifier_Config() object,
      *                      an array of directives based on loadArray(),
      *                      or a string filename of an ini file.
      * @param HTMLPurifier_ConfigSchema $schema Schema object
      * @return HTMLPurifier_Config Configured object
      */
     public static function create($config, $schema = null)
     {
         if ($config instanceof HTMLPurifier_Config) {
             // pass-through
             return $config;
         }
         if (!$schema) {
             $ret = HTMLPurifier_Config::createDefault();
         } else {
             $ret = new HTMLPurifier_Config($schema);
         }
         if (is_string($config)) {
             $ret->loadIni($config);
         } elseif (is_array($config)) $ret->loadArray($config);
         return $ret;
     }
 
     /**
      * Creates a new config object that inherits from a previous one.
      * @param HTMLPurifier_Config $config Configuration object to inherit from.
      * @return HTMLPurifier_Config object with $config as its parent.
      */
     public static function inherit(HTMLPurifier_Config $config)
     {
         return new HTMLPurifier_Config($config->def, $config->plist);
     }
 
     /**
      * Convenience constructor that creates a default configuration object.
      * @return HTMLPurifier_Config default object.
      */
     public static function createDefault()
     {
         $definition = HTMLPurifier_ConfigSchema::instance();
         $config = new HTMLPurifier_Config($definition);
         return $config;
     }
 
     /**
      * Retrieves a value from the configuration.
      *
      * @param string $key String key
      * @param mixed $a
      *
      * @return mixed
      */
     public function get($key, $a = null)
     {
         if ($a !== null) {
             $this->triggerError(
                 "Using deprecated API: use \$config->get('$key.$a') instead",
                 E_USER_WARNING
             );
             $key = "$key.$a";
         }
         if (!$this->finalized) {
             $this->autoFinalize();
         }
         if (!isset($this->def->info[$key])) {
             // can't add % due to SimpleTest bug
             $this->triggerError(
                 'Cannot retrieve value of undefined directive ' . htmlspecialchars($key),
                 E_USER_WARNING
             );
             return;
         }
         if (isset($this->def->info[$key]->isAlias)) {
             $d = $this->def->info[$key];
             $this->triggerError(
                 'Cannot get value from aliased directive, use real name ' . $d->key,
                 E_USER_ERROR
             );
             return;
         }
         if ($this->lock) {
             list($ns) = explode('.', $key);
             if ($ns !== $this->lock) {
                 $this->triggerError(
                     'Cannot get value of namespace ' . $ns . ' when lock for ' .
                     $this->lock .
                     ' is active, this probably indicates a Definition setup method ' .
                     'is accessing directives that are not within its namespace',
                     E_USER_ERROR
                 );
                 return;
             }
         }
         return $this->plist->get($key);
     }
 
     /**
      * Retrieves an array of directives to values from a given namespace
      *
      * @param string $namespace String namespace
      *
      * @return array
      */
     public function getBatch($namespace)
     {
         if (!$this->finalized) {
             $this->autoFinalize();
         }
         $full = $this->getAll();
         if (!isset($full[$namespace])) {
             $this->triggerError(
                 'Cannot retrieve undefined namespace ' .
                 htmlspecialchars($namespace),
                 E_USER_WARNING
             );
             return;
         }
         return $full[$namespace];
     }
 
     /**
      * Returns a SHA-1 signature of a segment of the configuration object
      * that uniquely identifies that particular configuration
      *
      * @param string $namespace Namespace to get serial for
      *
      * @return string
      * @note Revision is handled specially and is removed from the batch
      *       before processing!
      */
     public function getBatchSerial($namespace)
     {
         if (empty($this->serials[$namespace])) {
             $batch = $this->getBatch($namespace);
             unset($batch['DefinitionRev']);
             $this->serials[$namespace] = sha1(serialize($batch));
         }
         return $this->serials[$namespace];
     }
 
     /**
      * Returns a SHA-1 signature for the entire configuration object
      * that uniquely identifies that particular configuration
      *
      * @return string
      */
     public function getSerial()
     {
         if (empty($this->serial)) {
             $this->serial = sha1(serialize($this->getAll()));
         }
         return $this->serial;
     }
 
     /**
      * Retrieves all directives, organized by namespace
      *
      * @warning This is a pretty inefficient function, avoid if you can
      */
     public function getAll()
     {
         if (!$this->finalized) {
             $this->autoFinalize();
         }
         $ret = array();
         foreach ($this->plist->squash() as $name => $value) {
             list($ns, $key) = explode('.', $name, 2);
             $ret[$ns][$key] = $value;
         }
         return $ret;
     }
 
     /**
      * Sets a value to configuration.
      *
      * @param string $key key
      * @param mixed $value value
      * @param mixed $a
      */
     public function set($key, $value, $a = null)
     {
         if (strpos($key, '.') === false) {
             $namespace = $key;
             $directive = $value;
             $value = $a;
             $key = "$key.$directive";
             $this->triggerError("Using deprecated API: use \$config->set('$key', ...) instead", E_USER_NOTICE);
         } else {
             list($namespace) = explode('.', $key);
         }
         if ($this->isFinalized('Cannot set directive after finalization')) {
             return;
         }
         if (!isset($this->def->info[$key])) {
             $this->triggerError(
                 'Cannot set undefined directive ' . htmlspecialchars($key) . ' to value',
                 E_USER_WARNING
             );
             return;
         }
         $def = $this->def->info[$key];
 
         if (isset($def->isAlias)) {
             if ($this->aliasMode) {
                 $this->triggerError(
                     'Double-aliases not allowed, please fix '.
                     'ConfigSchema bug with' . $key,
                     E_USER_ERROR
                 );
                 return;
             }
             $this->aliasMode = true;
             $this->set($def->key, $value);
             $this->aliasMode = false;
             $this->triggerError("$key is an alias, preferred directive name is {$def->key}", E_USER_NOTICE);
             return;
         }
 
         // Raw type might be negative when using the fully optimized form
         // of stdClass, which indicates allow_null == true
         $rtype = is_int($def) ? $def : $def->type;
         if ($rtype < 0) {
             $type = -$rtype;
             $allow_null = true;
         } else {
             $type = $rtype;
             $allow_null = isset($def->allow_null);
         }
 
         try {
             $value = $this->parser->parse($value, $type, $allow_null);
         } catch (HTMLPurifier_VarParserException $e) {
             $this->triggerError(
                 'Value for ' . $key . ' is of invalid type, should be ' .
                 HTMLPurifier_VarParser::getTypeName($type),
                 E_USER_WARNING
             );
             return;
         }
         if (is_string($value) && is_object($def)) {
             // resolve value alias if defined
             if (isset($def->aliases[$value])) {
                 $value = $def->aliases[$value];
             }
             // check to see if the value is allowed
             if (isset($def->allowed) && !isset($def->allowed[$value])) {
                 $this->triggerError(
                     'Value not supported, valid values are: ' .
                     $this->_listify($def->allowed),
                     E_USER_WARNING
                 );
                 return;
             }
         }
         $this->plist->set($key, $value);
 
         // reset definitions if the directives they depend on changed
         // this is a very costly process, so it's discouraged
         // with finalization
         if ($namespace == 'HTML' || $namespace == 'CSS' || $namespace == 'URI') {
             $this->definitions[$namespace] = null;
         }
 
         $this->serials[$namespace] = false;
     }
 
     /**
      * Convenience function for error reporting
      *
      * @param array $lookup
      *
      * @return string
      */
     private function _listify($lookup)
     {
         $list = array();
         foreach ($lookup as $name => $b) {
             $list[] = $name;
         }
         return implode(', ', $list);
     }
 
     /**
      * Retrieves object reference to the HTML definition.
      *
      * @param bool $raw Return a copy that has not been setup yet. Must be
      *             called before it's been setup, otherwise won't work.
      * @param bool $optimized If true, this method may return null, to
      *             indicate that a cached version of the modified
      *             definition object is available and no further edits
      *             are necessary.  Consider using
      *             maybeGetRawHTMLDefinition, which is more explicitly
      *             named, instead.
      *
      * @return HTMLPurifier_HTMLDefinition
      */
     public function getHTMLDefinition($raw = false, $optimized = false)
     {
         return $this->getDefinition('HTML', $raw, $optimized);
     }
 
     /**
      * Retrieves object reference to the CSS definition
      *
      * @param bool $raw Return a copy that has not been setup yet. Must be
      *             called before it's been setup, otherwise won't work.
      * @param bool $optimized If true, this method may return null, to
      *             indicate that a cached version of the modified
      *             definition object is available and no further edits
      *             are necessary.  Consider using
      *             maybeGetRawCSSDefinition, which is more explicitly
      *             named, instead.
      *
      * @return HTMLPurifier_CSSDefinition
      */
     public function getCSSDefinition($raw = false, $optimized = false)
     {
         return $this->getDefinition('CSS', $raw, $optimized);
     }
 
     /**
      * Retrieves object reference to the URI definition
      *
      * @param bool $raw Return a copy that has not been setup yet. Must be
      *             called before it's been setup, otherwise won't work.
      * @param bool $optimized If true, this method may return null, to
      *             indicate that a cached version of the modified
      *             definition object is available and no further edits
      *             are necessary.  Consider using
      *             maybeGetRawURIDefinition, which is more explicitly
      *             named, instead.
      *
      * @return HTMLPurifier_URIDefinition
      */
     public function getURIDefinition($raw = false, $optimized = false)
     {
         return $this->getDefinition('URI', $raw, $optimized);
     }
 
     /**
      * Retrieves a definition
      *
      * @param string $type Type of definition: HTML, CSS, etc
      * @param bool $raw Whether or not definition should be returned raw
      * @param bool $optimized Only has an effect when $raw is true.  Whether
      *        or not to return null if the result is already present in
      *        the cache.  This is off by default for backwards
      *        compatibility reasons, but you need to do things this
      *        way in order to ensure that caching is done properly.
      *        Check out enduser-customize.html for more details.
      *        We probably won't ever change this default, as much as the
      *        maybe semantics is the "right thing to do."
      *
      * @throws HTMLPurifier_Exception
      * @return HTMLPurifier_Definition
      */
     public function getDefinition($type, $raw = false, $optimized = false)
     {
         if ($optimized && !$raw) {
             throw new HTMLPurifier_Exception("Cannot set optimized = true when raw = false");
         }
         if (!$this->finalized) {
             $this->autoFinalize();
         }
         // temporarily suspend locks, so we can handle recursive definition calls
         $lock = $this->lock;
         $this->lock = null;
         $factory = HTMLPurifier_DefinitionCacheFactory::instance();
         $cache = $factory->create($type, $this);
         $this->lock = $lock;
         if (!$raw) {
             // full definition
             // ---------------
             // check if definition is in memory
             if (!empty($this->definitions[$type])) {
                 $def = $this->definitions[$type];
                 // check if the definition is setup
                 if ($def->setup) {
                     return $def;
                 } else {
                     $def->setup($this);
                     if ($def->optimized) {
                         $cache->add($def, $this);
                     }
                     return $def;
                 }
             }
             // check if definition is in cache
             $def = $cache->get($this);
             if ($def) {
                 // definition in cache, save to memory and return it
                 $this->definitions[$type] = $def;
                 return $def;
             }
             // initialize it
             $def = $this->initDefinition($type);
             // set it up
             $this->lock = $type;
             $def->setup($this);
             $this->lock = null;
             // save in cache
             $cache->add($def, $this);
             // return it
             return $def;
         } else {
             // raw definition
             // --------------
             // check preconditions
             $def = null;
             if ($optimized) {
                 if (is_null($this->get($type . '.DefinitionID'))) {
                     // fatally error out if definition ID not set
                     throw new HTMLPurifier_Exception(
                         "Cannot retrieve raw version without specifying %$type.DefinitionID"
                     );
                 }
             }
             if (!empty($this->definitions[$type])) {
                 $def = $this->definitions[$type];
                 if ($def->setup && !$optimized) {
                     $extra = $this->chatty ?
                         " (try moving this code block earlier in your initialization)" :
                         "";
                     throw new HTMLPurifier_Exception(
                         "Cannot retrieve raw definition after it has already been setup" .
                         $extra
                     );
                 }
                 if ($def->optimized === null) {
                     $extra = $this->chatty ? " (try flushing your cache)" : "";
                     throw new HTMLPurifier_Exception(
                         "Optimization status of definition is unknown" . $extra
                     );
                 }
                 if ($def->optimized !== $optimized) {
                     $msg = $optimized ? "optimized" : "unoptimized";
                     $extra = $this->chatty ?
                         " (this backtrace is for the first inconsistent call, which was for a $msg raw definition)"
                         : "";
                     throw new HTMLPurifier_Exception(
                         "Inconsistent use of optimized and unoptimized raw definition retrievals" . $extra
                     );
                 }
             }
             // check if definition was in memory
             if ($def) {
                 if ($def->setup) {
                     // invariant: $optimized === true (checked above)
                     return null;
                 } else {
                     return $def;
                 }
             }
             // if optimized, check if definition was in cache
             // (because we do the memory check first, this formulation
             // is prone to cache slamming, but I think
             // guaranteeing that either /all/ of the raw
             // setup code or /none/ of it is run is more important.)
             if ($optimized) {
                 // This code path only gets run once; once we put
                 // something in $definitions (which is guaranteed by the
                 // trailing code), we always short-circuit above.
                 $def = $cache->get($this);
                 if ($def) {
                     // save the full definition for later, but don't
                     // return it yet
                     $this->definitions[$type] = $def;
                     return null;
                 }
             }
             // check invariants for creation
             if (!$optimized) {
                 if (!is_null($this->get($type . '.DefinitionID'))) {
                     if ($this->chatty) {
                         $this->triggerError(
                             'Due to a documentation error in previous version of HTML Purifier, your ' .
                             'definitions are not being cached.  If this is OK, you can remove the ' .
                             '%$type.DefinitionRev and %$type.DefinitionID declaration.  Otherwise, ' .
                             'modify your code to use maybeGetRawDefinition, and test if the returned ' .
                             'value is null before making any edits (if it is null, that means that a ' .
                             'cached version is available, and no raw operations are necessary).  See ' .
                             '<a href="http://htmlpurifier.org/docs/enduser-customize.html#optimized">' .
                             'Customize</a> for more details',
                             E_USER_WARNING
                         );
                     } else {
                         $this->triggerError(
                             "Useless DefinitionID declaration",
                             E_USER_WARNING
                         );
                     }
                 }
             }
             // initialize it
             $def = $this->initDefinition($type);
             $def->optimized = $optimized;
             return $def;
         }
         throw new HTMLPurifier_Exception("The impossible happened!");
     }
 
     /**
      * Initialise definition
      *
      * @param string $type What type of definition to create
      *
      * @return HTMLPurifier_CSSDefinition|HTMLPurifier_HTMLDefinition|HTMLPurifier_URIDefinition
      * @throws HTMLPurifier_Exception
      */
     private function initDefinition($type)
     {
         // quick checks failed, let's create the object
         if ($type == 'HTML') {
             $def = new HTMLPurifier_HTMLDefinition();
         } elseif ($type == 'CSS') {
             $def = new HTMLPurifier_CSSDefinition();
         } elseif ($type == 'URI') {
             $def = new HTMLPurifier_URIDefinition();
         } else {
             throw new HTMLPurifier_Exception(
                 "Definition of $type type not supported"
             );
         }
         $this->definitions[$type] = $def;
         return $def;
     }
 
     public function maybeGetRawDefinition($name)
     {
         return $this->getDefinition($name, true, true);
     }
 
     /**
      * @return HTMLPurifier_HTMLDefinition
      */
     public function maybeGetRawHTMLDefinition()
     {
         return $this->getDefinition('HTML', true, true);
     }
     
     /**
      * @return HTMLPurifier_CSSDefinition
      */
     public function maybeGetRawCSSDefinition()
     {
         return $this->getDefinition('CSS', true, true);
     }
     
     /**
      * @return HTMLPurifier_URIDefinition
      */
     public function maybeGetRawURIDefinition()
     {
         return $this->getDefinition('URI', true, true);
     }
 
     /**
      * Loads configuration values from an array with the following structure:
      * Namespace.Directive => Value
      *
      * @param array $config_array Configuration associative array
      */
     public function loadArray($config_array)
     {
         if ($this->isFinalized('Cannot load directives after finalization')) {
             return;
         }
         foreach ($config_array as $key => $value) {
             $key = str_replace('_', '.', $key);
             if (strpos($key, '.') !== false) {
                 $this->set($key, $value);
             } else {
                 $namespace = $key;
                 $namespace_values = $value;
                 foreach ($namespace_values as $directive => $value2) {
                     $this->set($namespace .'.'. $directive, $value2);
                 }
             }
         }
     }
 
     /**
      * Returns a list of array(namespace, directive) for all directives
      * that are allowed in a web-form context as per an allowed
      * namespaces/directives list.
      *
      * @param array $allowed List of allowed namespaces/directives
      * @param HTMLPurifier_ConfigSchema $schema Schema to use, if not global copy
      *
      * @return array
      */
     public static function getAllowedDirectivesForForm($allowed, $schema = null)
     {
         if (!$schema) {
             $schema = HTMLPurifier_ConfigSchema::instance();
         }
         if ($allowed !== true) {
             if (is_string($allowed)) {
                 $allowed = array($allowed);
             }
             $allowed_ns = array();
             $allowed_directives = array();
             $blacklisted_directives = array();
             foreach ($allowed as $ns_or_directive) {
                 if (strpos($ns_or_directive, '.') !== false) {
                     // directive
                     if ($ns_or_directive[0] == '-') {
                         $blacklisted_directives[substr($ns_or_directive, 1)] = true;
                     } else {
                         $allowed_directives[$ns_or_directive] = true;
                     }
                 } else {
                     // namespace
                     $allowed_ns[$ns_or_directive] = true;
                 }
             }
         }
         $ret = array();
         foreach ($schema->info as $key => $def) {
             list($ns, $directive) = explode('.', $key, 2);
             if ($allowed !== true) {
                 if (isset($blacklisted_directives["$ns.$directive"])) {
                     continue;
                 }
                 if (!isset($allowed_directives["$ns.$directive"]) && !isset($allowed_ns[$ns])) {
                     continue;
                 }
             }
             if (isset($def->isAlias)) {
                 continue;
             }
             if ($directive == 'DefinitionID' || $directive == 'DefinitionRev') {
                 continue;
             }
             $ret[] = array($ns, $directive);
         }
         return $ret;
     }
 
     /**
      * Loads configuration values from $_GET/$_POST that were posted
      * via ConfigForm
      *
      * @param array $array $_GET or $_POST array to import
      * @param string|bool $index Index/name that the config variables are in
      * @param array|bool $allowed List of allowed namespaces/directives
      * @param bool $mq_fix Boolean whether or not to enable magic quotes fix
      * @param HTMLPurifier_ConfigSchema $schema Schema to use, if not global copy
      *
      * @return mixed
      */
     public static function loadArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true, $schema = null)
     {
         $ret = HTMLPurifier_Config::prepareArrayFromForm($array, $index, $allowed, $mq_fix, $schema);
         $config = HTMLPurifier_Config::create($ret, $schema);
         return $config;
     }
 
     /**
      * Merges in configuration values from $_GET/$_POST to object. NOT STATIC.
      *
      * @param array $array $_GET or $_POST array to import
      * @param string|bool $index Index/name that the config variables are in
      * @param array|bool $allowed List of allowed namespaces/directives
      * @param bool $mq_fix Boolean whether or not to enable magic quotes fix
      */
     public function mergeArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true)
     {
          $ret = HTMLPurifier_Config::prepareArrayFromForm($array, $index, $allowed, $mq_fix, $this->def);
          $this->loadArray($ret);
     }
 
     /**
      * Prepares an array from a form into something usable for the more
      * strict parts of HTMLPurifier_Config
      *
      * @param array $array $_GET or $_POST array to import
      * @param string|bool $index Index/name that the config variables are in
      * @param array|bool $allowed List of allowed namespaces/directives
      * @param bool $mq_fix Boolean whether or not to enable magic quotes fix
      * @param HTMLPurifier_ConfigSchema $schema Schema to use, if not global copy
      *
      * @return array
      */
     public static function prepareArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true, $schema = null)
     {
         if ($index !== false) {
             $array = (isset($array[$index]) && is_array($array[$index])) ? $array[$index] : array();
         }
         $mq = $mq_fix && function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc();
 
         $allowed = HTMLPurifier_Config::getAllowedDirectivesForForm($allowed, $schema);
         $ret = array();
         foreach ($allowed as $key) {
             list($ns, $directive) = $key;
             $skey = "$ns.$directive";
             if (!empty($array["Null_$skey"])) {
                 $ret[$ns][$directive] = null;
                 continue;
             }
             if (!isset($array[$skey])) {
                 continue;
             }
             $value = $mq ? stripslashes($array[$skey]) : $array[$skey];
             $ret[$ns][$directive] = $value;
         }
         return $ret;
     }
 
     /**
      * Loads configuration values from an ini file
      *
      * @param string $filename Name of ini file
      */
     public function loadIni($filename)
     {
         if ($this->isFinalized('Cannot load directives after finalization')) {
             return;
         }
         $array = parse_ini_file($filename, true);
         $this->loadArray($array);
     }
 
     /**
      * Checks whether or not the configuration object is finalized.
      *
      * @param string|bool $error String error message, or false for no error
      *
      * @return bool
      */
     public function isFinalized($error = false)
     {
         if ($this->finalized && $error) {
             $this->triggerError($error, E_USER_ERROR);
         }
         return $this->finalized;
     }
 
     /**
      * Finalizes configuration only if auto finalize is on and not
      * already finalized
      */
     public function autoFinalize()
     {
         if ($this->autoFinalize) {
             $this->finalize();
         } else {
             $this->plist->squash(true);
         }
     }
 
     /**
      * Finalizes a configuration object, prohibiting further change
      */
     public function finalize()
     {
         $this->finalized = true;
         $this->parser = null;
     }
 
     /**
      * Produces a nicely formatted error message by supplying the
      * stack frame information OUTSIDE of HTMLPurifier_Config.
      *
      * @param string $msg An error message
      * @param int $no An error number
      */
     protected function triggerError($msg, $no)
     {
         // determine previous stack frame
         $extra = '';
         if ($this->chatty) {
             $trace = debug_backtrace();
             // zip(tail(trace), trace) -- but PHP is not Haskell har har
             for ($i = 0, $c = count($trace); $i < $c - 1; $i++) {
                 // XXX this is not correct on some versions of HTML Purifier
                 if ($trace[$i + 1]['class'] === 'HTMLPurifier_Config') {
                     continue;
                 }
                 $frame = $trace[$i];
                 $extra = " invoked on line {$frame['line']} in file {$frame['file']}";
                 break;
             }
         }
         trigger_error($msg . $extra, $no);
     }
 
     /**
      * Returns a serialized form of the configuration object that can
      * be reconstituted.
      *
      * @return string
      */
     public function serialize()
     {
         $this->getDefinition('HTML');
         $this->getDefinition('CSS');
         $this->getDefinition('URI');
         return serialize($this);
     }
 
 }
 
 // vim: et sw=4 sts=4