diff options
Diffstat (limited to 'library/HTMLPurifier/Injector.php')
| -rw-r--r-- | library/HTMLPurifier/Injector.php | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/library/HTMLPurifier/Injector.php b/library/HTMLPurifier/Injector.php new file mode 100644 index 000000000..5922f8130 --- /dev/null +++ b/library/HTMLPurifier/Injector.php @@ -0,0 +1,239 @@ +<?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 |