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- <?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
- */
- public $name;
- /**
- * Instance of HTMLPurifier_HTMLDefinition
- */
- protected $htmlDefinition;
- /**
- * Reference to CurrentNesting variable in Context. This is an array
- * list of tokens that we are currently "inside"
- */
- protected $currentNesting;
- /**
- * Reference to InputTokens variable in Context. This is an array
- * list of the input tokens that are being processed.
- */
- protected $inputTokens;
- /**
- * Reference to InputIndex variable in Context. This is an integer
- * array index for $this->inputTokens that indicates what token
- * is currently being processed.
- */
- protected $inputIndex;
- /**
- * 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')
- */
- public $needed = array();
- /**
- * Index of inputTokens to rewind to.
- */
- protected $rewind = false;
- /**
- * Rewind to a spot to re-perform processing. This is useful if you
- * deleted a node, and now need to see if this change affected any
- * earlier nodes. Rewinding does not affect other injectors, and can
- * result in infinite loops if not used carefully.
- * @warning HTML Purifier will prevent you from fast-forwarding with this
- * function.
- */
- public function rewind($index) {
- $this->rewind = $index;
- }
- /**
- * Retrieves rewind, and then unsets it.
- */
- public function getRewind() {
- $r = $this->rewind;
- $this->rewind = 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 $config Instance of HTMLPurifier_Config
- * @param $context Instance of HTMLPurifier_Context
- * @return Boolean false if success, string of missing needed element/attribute if failure
- */
- public function prepare($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->inputTokens =& $context->get('InputTokens');
- $this->inputIndex =& $context->get('InputIndex');
- 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 $config Instance of HTMLPurifier_Config
- * @param $context Instance of HTMLPurifier_Context
- * @return Boolean false if success, string of missing needed element/attribute if failure
- */
- public function checkNeeded($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 $name Name of element to test for
- * @return True if element is allowed, false if it is not
- */
- public function allowsElement($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 $i = null beforehand!
- * @param &$i Current integer index variable for inputTokens
- * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
- */
- protected function forward(&$i, &$current) {
- if ($i === null) $i = $this->inputIndex + 1;
- else $i++;
- if (!isset($this->inputTokens[$i])) return false;
- $current = $this->inputTokens[$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 $this->inputIndex starts in.
- */
- protected function forwardUntilEndToken(&$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 $i = null beforehand!
- * @param &$i Current integer index variable for inputTokens
- * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
- */
- protected function backward(&$i, &$current) {
- if ($i === null) $i = $this->inputIndex - 1;
- else $i--;
- if ($i < 0) return false;
- $current = $this->inputTokens[$i];
- return true;
- }
- /**
- * Initializes the iterator at the current position. Use in a do {} while;
- * loop to force the _forward and _backward functions to start at the
- * current location.
- * @warning Please prevent previous references from interfering with this
- * functions by setting $i = null beforehand!
- * @param &$i Current integer index variable for inputTokens
- * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
- */
- protected function current(&$i, &$current) {
- if ($i === null) $i = $this->inputIndex;
- $current = $this->inputTokens[$i];
- }
- /**
- * 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
- * @note This differs from handlers in that the token is read-only
- * @deprecated
- */
- public function notifyEnd($token) {}
- }
- // vim: et sw=4 sts=4
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