<?php
/**
* Takes tokens makes them well-formed (balance end tags, etc.)
*/
class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
{
/**
* Locally shared variable references
*/
protected $inputTokens, $inputIndex, $outputTokens, $currentNesting,
$currentInjector, $injectors;
public function execute($tokens, $config, $context) {
$definition = $config->getHTMLDefinition();
// local variables
$generator = new HTMLPurifier_Generator($config, $context);
$escape_invalid_tags = $config->get('Core', 'EscapeInvalidTags');
$e = $context->get('ErrorCollector', true);
// member variables
$this->currentNesting = array();
$this->inputIndex = false;
$this->inputTokens =& $tokens;
$this->config = $config;
$this->context = $context;
// context variables
$context->register('CurrentNesting', $this->currentNesting);
$context->register('InputIndex', $this->inputIndex);
$context->register('InputTokens', $tokens);
// -- begin INJECTOR --
$this->injectors = array();
$injectors = $config->getBatch('AutoFormat');
$def_injectors = $definition->info_injector;
$custom_injectors = $injectors['Custom'];
unset($injectors['Custom']); // special case
foreach ($injectors as $injector => $b) {
$injector = "HTMLPurifier_Injector_$injector";
if (!$b) continue;
$this->injectors[] = new $injector;
}
foreach ($def_injectors as $injector) {
// assumed to be objects
$this->injectors[] = $injector;
}
foreach ($custom_injectors as $injector) {
if (is_string($injector)) {
$injector = "HTMLPurifier_Injector_$injector";
$injector = new $injector;
}
$this->injectors[] = $injector;
}
// array index of the injector that resulted in an array
// substitution. This enables processTokens() to know which
// injectors are affected by the added tokens and which are
// not (namely, the ones after the current injector are not
// affected)
$this->currentInjector = false;
// give the injectors references to the definition and context
// variables for performance reasons
foreach ($this->injectors as $i => $injector) {
$error = $injector->prepare($config, $context);
if (!$error) continue;
array_splice($this->injectors, $i, 1); // rm the injector
trigger_error("Cannot enable {$injector->name} injector because $error is not allowed", E_USER_WARNING);
}
// warning: most foreach loops follow the convention $i => $injector.
// Don't define these as loop-wide variables, please!
// -- end INJECTOR --
$token = false;
$context->register('CurrentToken', $token);
// isset is in loop because $tokens size changes during loop exec
for (
$this->inputIndex = 0;
$this->inputIndex == 0 || isset($tokens[$this->inputIndex - 1]);
$this->inputIndex++
) {
foreach ($this->injectors as $injector) {
if ($injector->skip > 0) $injector->skip--;
}
// handle case of document end
if (!isset($tokens[$this->inputIndex])) {
// we're at the end now, fix all still unclosed tags (this is
// duplicated from the end of the loop with some slight modifications)
// not using $skipped_tags since it would invariably be all of them
if (!empty($this->currentNesting)) {
$top_nesting = array_pop($this->currentNesting);
// please don't redefine $i!
if ($e && !isset($top_nesting->armor['MakeWellFormed_TagClosedError'])) {
$e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by document end', $top_nesting);
}
// instead of splice, since we know this is the end
$new_token = new HTMLPurifier_Token_End($top_nesting->name);
$tokens[] = $new_token;
$this->currentNesting[] = $top_nesting;
--$this->inputIndex;
// punt to the regular code to handle the new token
continue;
}
break;
}
// if all goes well, this token will be passed through unharmed
$token = $tokens[$this->inputIndex];
//echo '<hr>';
//printTokens($tokens, $this->inputIndex);
//var_dump($this->currentNesting);
// quick-check: if it's not a tag, no need to process
if (empty( $token->is_tag )) {
if ($token instanceof HTMLPurifier_Token_Text) {
// injector handler code; duplicated for performance reasons
foreach ($this->injectors as $i => $injector) {
if (!$injector->skip) $injector->handleText($token);
if (is_array($token) || is_int($token)) {
$this->currentInjector = $i;
break;
}
}
}
$this->processToken($token, $config, $context);
continue;
}
if (isset($definition->info[$token->name])) {
$type = $definition->info[$token->name]->child->type;
} else {
$type = false; // Type is unknown, treat accordingly
}
// quick tag checks: anything that's *not* an end tag
$ok = false;
if ($type === 'empty' && $token instanceof HTMLPurifier_Token_Start) {
// test if it claims to be a start tag but is empty
$token = new HTMLPurifier_Token_Empty($token->name, $token->attr);
$ok = true;
} elseif ($type && $type !== 'empty' && $token instanceof HTMLPurifier_Token_Empty) {
// claims to be empty but really is a start tag
$token = array(
new HTMLPurifier_Token_Start($token->name, $token->attr),
new HTMLPurifier_Token_End($token->name)
);
$ok = true;
} elseif ($token instanceof HTMLPurifier_Token_Empty) {
// real empty token
$ok = true;
} elseif ($token instanceof HTMLPurifier_Token_Start) {
// start tag
// ...unless they also have to close their parent
if (!empty($this->currentNesting)) {
$parent = array_pop($this->currentNesting);
if (isset($definition->info[$parent->name])) {
$elements = $definition->info[$parent->name]->child->getNonAutoCloseElements($config);
$autoclose = !isset($elements[$token->name]);
} else {
$autoclose = false;
}
if ($autoclose) {
if ($e) $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag auto closed', $parent);
// insert parent end tag before this tag;
// end tag isn't processed, but this tag is processed again
$new_token = new HTMLPurifier_Token_End($parent->name);
$new_token->start = $parent;
$this->insertBefore($new_token);
continue;
}
$this->currentNesting[] = $parent; // undo the pop
}
$ok = true;
}
// injector handler code; duplicated for performance reasons
if ($ok) {
foreach ($this->injectors as $i => $injector) {
if (!$injector->skip) $injector->handleElement($token);
if (is_array($token) || is_int($token)) {
$this->currentInjector = $i;
break;
}
}
$this->processToken($token, $config, $context);
continue;
}
// sanity check: we should be dealing with a closing tag
if (!$token instanceof HTMLPurifier_Token_End) {
$this->remove();
continue;
}
// make sure that we have something open
if (empty($this->currentNesting)) {
if ($escape_invalid_tags) {
if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag to text');
$this->swap(new HTMLPurifier_Token_Text(
$generator->generateFromToken($token)
));
} else {
$this->remove();
if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag removed');
}
continue;
}
if (!$this->handleEnd($token)) continue;
// first, check for the simplest case: everything closes neatly
$current_parent = array_pop($this->currentNesting);
if ($current_parent->name == $token->name) {
$token->start = $current_parent;
continue;
}
// okay, so we're trying to close the wrong tag
// undo the pop previous pop
$this->currentNesting[] = $current_parent;
// scroll back the entire nest, trying to find our tag.
// (feature could be to specify how far you'd like to go)
$size = count($this->currentNesting);
// -2 because -1 is the last element, but we already checked that
$skipped_tags = false;
for ($i = $size - 2; $i >= 0; $i--) {
if ($this->currentNesting[$i]->name == $token->name) {
// current nesting is modified
$skipped_tags = array_splice($this->currentNesting, $i);
break;
}
}
// we still didn't find the tag, so remove
if ($skipped_tags === false) {
if ($escape_invalid_tags) {
$this->swap(new HTMLPurifier_Token_Text(
$generator->generateFromToken($token)
));
if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag to text');
} else {
$this->remove();
if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag removed');
}
continue;
}
// okay, we found it, close all the skipped tags
// note that skipped tags contains the element we need closed
$this->remove();
for ($i = count($skipped_tags) - 1; $i >= 0; $i--) {
// please don't redefine $i!
if ($i && $e && !isset($skipped_tags[$i]->armor['MakeWellFormed_TagClosedError'])) {
$e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by element end', $skipped_tags[$i]);
}
$new_token = new HTMLPurifier_Token_End($skipped_tags[$i]->name);
$new_token->start = $skipped_tags[$i];
$this->insertAfter($new_token);
//printTokens($tokens, $this->inputIndex);
//var_dump($this->currentNesting);
}
}
$context->destroy('CurrentNesting');
$context->destroy('InputTokens');
$context->destroy('InputIndex');
$context->destroy('CurrentToken');
unset($this->outputTokens, $this->injectors, $this->currentInjector,
$this->currentNesting, $this->inputTokens, $this->inputIndex);
return $tokens;
}
/**
* Inserts a token before the current token. Cursor now points to this token.
*/
protected function insertBefore($token) {
array_splice($this->inputTokens, $this->inputIndex, 0, array($token));
}
/**
* Inserts a token after the current token. Cursor now points to this token.
*/
protected function insertAfter($token) {
array_splice($this->inputTokens, ++$this->inputIndex, 0, array($token));
}
/**
* Removes current token. Cursor now points to previous token.
*/
protected function remove() {
array_splice($this->inputTokens, $this->inputIndex--, 1);
}
/**
* Swap current token with new token. Cursor points to new token (no change).
*/
protected function swap($token) {
array_splice($this->inputTokens, $this->inputIndex, 1, array($token));
}
/**
* Processes arbitrary token values for complicated substitution patterns.
* In general:
*
* If $token is an array, it is a list of tokens to substitute for the
* current token. These tokens then get individually processed.
*
* If $token is a regular token, it is swapped with the current token,
* and the stack is updated.
*
* If $token is false, the current token is deleted.
*/
protected function processToken($token, $config, $context, $is_end = false) {
if (is_array($token) || is_int($token)) {
// the original token was overloaded by an injector, time
// to some fancy acrobatics
if (is_array($token)) {
array_splice($this->inputTokens, $this->inputIndex, 1, $token);
} else {
array_splice($this->inputTokens, $this->inputIndex, $token, array());
}
if ($this->injectors) {
if (!$this->checkRewind()) {
// adjust the injector skips based on the array substitution
$offset = is_array($token) ? count($token) : 0;
for ($i = 0; $i <= $this->currentInjector; $i++) {
// because of the skip back, we need to add one more
// for uninitialized injectors. I'm not exactly
// sure why this is the case, but I think it has to
// do with the fact that we're decrementing skips
// before re-checking text
if (!$this->injectors[$i]->skip) $this->injectors[$i]->skip++;
$this->injectors[$i]->skip += $offset;
}
}
}
// ensure that we reprocess these tokens with the other injectors
--$this->inputIndex;
} elseif ($token) {
if ($is_end) {
$this->swap($token);
if (!$token instanceof HTMLPurifier_Token_End) {
--$this->inputIndex;
}
} else {
// regular case
$this->swap($token);
if ($token instanceof HTMLPurifier_Token_Start) {
$this->currentNesting[] = $token;
} elseif ($token instanceof HTMLPurifier_Token_End) {
// not actually used
$token->start = array_pop($this->currentNesting);
}
}
} else {
$this->remove();
}
}
/**
* Checks for a rewind, adjusts the input index and skips accordingly.
*/
protected function checkRewind() {
$rewind = $this->injectors[$this->currentInjector]->getRewind();
if ($rewind < 0) $rewind = 0;
if (is_int($rewind)) {
$offset = $this->inputIndex - $rewind;
if ($this->injectors) {
foreach ($this->injectors as $i => $injector) {
if ($i == $this->currentInjector) {
$injector->skip = 0;
} else {
$injector->skip += $offset;
}
}
}
for ($this->inputIndex--; $this->inputIndex >= $rewind; $this->inputIndex--) {
$prev = $this->inputTokens[$this->inputIndex];
if ($prev instanceof HTMLPurifier_Token_Start) array_pop($this->currentNesting);
elseif ($prev instanceof HTMLPurifier_Token_End) $this->currentNesting[] = $prev->start;
}
$this->inputIndex++;
return true;
} else {
return false;
}
}
protected function handleEnd($token) {
foreach ($this->injectors as $i => $injector) {
if (!$injector->skip) $injector->handleEnd($token);
if (is_array($token) || is_int($token)) {
$this->currentInjector = $i;
break;
}
}
$this->processToken($token, $this->config, $this->context, true);
return $token instanceof HTMLPurifier_Token_End;
}
}