File indexing completed on 2024-05-05 06:02:16

 <?php
 
 /**
  * Injects tokens into the document while parsing for well-formedness.
  * This enables "formatter-like" functionality such as auto-paragraphing,
  * smiley-ification and linkification to take place.
  *
  * A note on how handlers create changes; this is done by assigning a new
  * value to the $token reference. These values can take a variety of forms and
  * are best described HTMLPurifier_Strategy_MakeWellFormed->processToken()
  * documentation.
  *
  * @todo Allow injectors to request a re-run on their output. This
  *       would help if an operation is recursive.
  */
 abstract class HTMLPurifier_Injector
 {
 
     /**
      * Advisory name of injector, this is for friendly error messages.
      * @type string
      */
     public $name;
 
     /**
      * @type HTMLPurifier_HTMLDefinition
      */
     protected $htmlDefinition;
 
     /**
      * Reference to CurrentNesting variable in Context. This is an array
      * list of tokens that we are currently "inside"
      * @type array
      */
     protected $currentNesting;
 
     /**
      * Reference to current token.
      * @type HTMLPurifier_Token
      */
     protected $currentToken;
 
     /**
      * Reference to InputZipper variable in Context.
      * @type HTMLPurifier_Zipper
      */
     protected $inputZipper;
 
     /**
      * Array of elements and attributes this injector creates and therefore
      * need to be allowed by the definition. Takes form of
      * array('element' => array('attr', 'attr2'), 'element2')
      * @type array
      */
     public $needed = array();
 
     /**
      * Number of elements to rewind backwards (relative).
      * @type bool|int
      */
     protected $rewindOffset = false;
 
     /**
      * Rewind to a spot to re-perform processing. This is useful if you
      * deleted a node, and now need to see if this change affected any
      * earlier nodes. Rewinding does not affect other injectors, and can
      * result in infinite loops if not used carefully.
      * @param bool|int $offset
      * @warning HTML Purifier will prevent you from fast-forwarding with this
      *          function.
      */
     public function rewindOffset($offset)
     {
         $this->rewindOffset = $offset;
     }
 
     /**
      * Retrieves rewind offset, and then unsets it.
      * @return bool|int
      */
     public function getRewindOffset()
     {
         $r = $this->rewindOffset;
         $this->rewindOffset = false;
         return $r;
     }
 
     /**
      * Prepares the injector by giving it the config and context objects:
      * this allows references to important variables to be made within
      * the injector. This function also checks if the HTML environment
      * will work with the Injector (see checkNeeded()).
      * @param HTMLPurifier_Config $config
      * @param HTMLPurifier_Context $context
      * @return bool|string Boolean false if success, string of missing needed element/attribute if failure
      */
     public function prepare($config, $context)
     {
         $this->htmlDefinition = $config->getHTMLDefinition();
         // Even though this might fail, some unit tests ignore this and
         // still test checkNeeded, so be careful. Maybe get rid of that
         // dependency.
         $result = $this->checkNeeded($config);
         if ($result !== false) {
             return $result;
         }
         $this->currentNesting =& $context->get('CurrentNesting');
         $this->currentToken   =& $context->get('CurrentToken');
         $this->inputZipper    =& $context->get('InputZipper');
         return false;
     }
 
     /**
      * This function checks if the HTML environment
      * will work with the Injector: if p tags are not allowed, the
      * Auto-Paragraphing injector should not be enabled.
      * @param HTMLPurifier_Config $config
      * @return bool|string Boolean false if success, string of missing needed element/attribute if failure
      */
     public function checkNeeded($config)
     {
         $def = $config->getHTMLDefinition();
         foreach ($this->needed as $element => $attributes) {
             if (is_int($element)) {
                 $element = $attributes;
             }
             if (!isset($def->info[$element])) {
                 return $element;
             }
             if (!is_array($attributes)) {
                 continue;
             }
             foreach ($attributes as $name) {
                 if (!isset($def->info[$element]->attr[$name])) {
                     return "$element.$name";
                 }
             }
         }
         return false;
     }
 
     /**
      * Tests if the context node allows a certain element
      * @param string $name Name of element to test for
      * @return bool True if element is allowed, false if it is not
      */
     public function allowsElement($name)
     {
         if (!empty($this->currentNesting)) {
             $parent_token = array_pop($this->currentNesting);
             $this->currentNesting[] = $parent_token;
             $parent = $this->htmlDefinition->info[$parent_token->name];
         } else {
             $parent = $this->htmlDefinition->info_parent_def;
         }
         if (!isset($parent->child->elements[$name]) || isset($parent->excludes[$name])) {
             return false;
         }
         // check for exclusion
         for ($i = count($this->currentNesting) - 2; $i >= 0; $i--) {
             $node = $this->currentNesting[$i];
             $def  = $this->htmlDefinition->info[$node->name];
             if (isset($def->excludes[$name])) {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * Iterator function, which starts with the next token and continues until
      * you reach the end of the input tokens.
      * @warning Please prevent previous references from interfering with this
      *          functions by setting $i = null beforehand!
      * @param int $i Current integer index variable for inputTokens
      * @param HTMLPurifier_Token $current Current token variable.
      *          Do NOT use $token, as that variable is also a reference
      * @return bool
      */
     protected function forward(&$i, &$current)
     {
         if ($i === null) {
             $i = count($this->inputZipper->back) - 1;
         } else {
             $i--;
         }
         if ($i < 0) {
             return false;
         }
         $current = $this->inputZipper->back[$i];
         return true;
     }
 
     /**
      * Similar to _forward, but accepts a third parameter $nesting (which
      * should be initialized at 0) and stops when we hit the end tag
      * for the node $this->inputIndex starts in.
      * @param int $i Current integer index variable for inputTokens
      * @param HTMLPurifier_Token $current Current token variable.
      *          Do NOT use $token, as that variable is also a reference
      * @param int $nesting
      * @return bool
      */
     protected function forwardUntilEndToken(&$i, &$current, &$nesting)
     {
         $result = $this->forward($i, $current);
         if (!$result) {
             return false;
         }
         if ($nesting === null) {
             $nesting = 0;
         }
         if ($current instanceof HTMLPurifier_Token_Start) {
             $nesting++;
         } elseif ($current instanceof HTMLPurifier_Token_End) {
             if ($nesting <= 0) {
                 return false;
             }
             $nesting--;
         }
         return true;
     }
 
     /**
      * Iterator function, starts with the previous token and continues until
      * you reach the beginning of input tokens.
      * @warning Please prevent previous references from interfering with this
      *          functions by setting $i = null beforehand!
      * @param int $i Current integer index variable for inputTokens
      * @param HTMLPurifier_Token $current Current token variable.
      *          Do NOT use $token, as that variable is also a reference
      * @return bool
      */
     protected function backward(&$i, &$current)
     {
         if ($i === null) {
             $i = count($this->inputZipper->front) - 1;
         } else {
             $i--;
         }
         if ($i < 0) {
             return false;
         }
         $current = $this->inputZipper->front[$i];
         return true;
     }
 
     /**
      * Handler that is called when a text token is processed
      */
     public function handleText(&$token)
     {
     }
 
     /**
      * Handler that is called when a start or empty token is processed
      */
     public function handleElement(&$token)
     {
     }
 
     /**
      * Handler that is called when an end token is processed
      */
     public function handleEnd(&$token)
     {
         $this->notifyEnd($token);
     }
 
     /**
      * Notifier that is called when an end token is processed
      * @param HTMLPurifier_Token $token Current token variable.
      * @note This differs from handlers in that the token is read-only
      * @deprecated
      */
     public function notifyEnd($token)
     {
     }
 }
 
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