0
0
mirror of https://github.com/ezyang/htmlpurifier.git synced 2024-11-14 01:08:41 +00:00
htmlpurifier/library/HTMLPurifier/Strategy/MakeWellFormed.php
2008-02-10 20:34:39 +00:00

298 lines
13 KiB
PHP

<?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
$result = array();
$generator = new HTMLPurifier_Generator();
$escape_invalid_tags = $config->get('Core', 'EscapeInvalidTags');
$e = $context->get('ErrorCollector', true);
// member variables
$this->currentNesting = array();
$this->inputIndex = false;
$this->inputTokens =& $tokens;
$this->outputTokens =& $result;
// 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');
$custom_injectors = $injectors['Custom'];
unset($injectors['Custom']); // special case
foreach ($injectors as $injector => $b) {
$injector = "HTMLPurifier_Injector_$injector";
if (!$b) continue;
$this->injectors[] = new $injector;
}
foreach ($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; isset($tokens[$this->inputIndex]); $this->inputIndex++) {
// if all goes well, this token will be passed through unharmed
$token = $tokens[$this->inputIndex];
//printTokens($tokens, $this->inputIndex);
foreach ($this->injectors as $injector) {
if ($injector->skip > 0) $injector->skip--;
}
// 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)) {
$this->currentInjector = $i;
break;
}
}
}
$this->processToken($token, $config, $context);
continue;
}
$info = $definition->info[$token->name]->child;
// quick tag checks: anything that's *not* an end tag
$ok = false;
if ($info->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);
$ok = true;
} elseif ($info->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);
$parent_info = $definition->info[$parent->name];
// this can be replaced with a more general algorithm:
// if the token is not allowed by the parent, auto-close
// the parent
if (!isset($parent_info->child->elements[$token->name])) {
if ($e) $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag auto closed', $parent);
// close the parent, then re-loop to reprocess token
$result[] = new HTMLPurifier_Token_End($parent->name);
$this->inputIndex--;
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)) {
$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) 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');
$result[] = new HTMLPurifier_Token_Text(
$generator->generateFromToken($token, $config, $context)
);
} elseif ($e) {
$e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag removed');
}
continue;
}
// first, check for the simplest case: everything closes neatly
$current_parent = array_pop($this->currentNesting);
if ($current_parent->name == $token->name) {
$result[] = $token;
foreach ($this->injectors as $i => $injector) {
$injector->notifyEnd($token);
}
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) {
$result[] = new HTMLPurifier_Token_Text(
$generator->generateFromToken($token, $config, $context)
);
if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag to text');
} elseif ($e) {
$e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag removed');
}
continue;
}
// okay, we found it, close all the skipped tags
// note that skipped tags contains the element we need closed
for ($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]);
}
$result[] = $new_token = new HTMLPurifier_Token_End($skipped_tags[$i]->name);
foreach ($this->injectors as $injector) {
$injector->notifyEnd($new_token);
}
}
}
$context->destroy('CurrentNesting');
$context->destroy('InputTokens');
$context->destroy('InputIndex');
$context->destroy('CurrentToken');
// 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)) {
for ($i = count($this->currentNesting) - 1; $i >= 0; $i--) {
// please don't redefine $i!
if ($e && !isset($this->currentNesting[$i]->armor['MakeWellFormed_TagClosedError'])) {
$e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by document end', $this->currentNesting[$i]);
}
$result[] = $new_token = new HTMLPurifier_Token_End($this->currentNesting[$i]->name);
foreach ($this->injectors as $injector) {
$injector->notifyEnd($new_token);
}
}
}
unset($this->outputTokens, $this->injectors, $this->currentInjector,
$this->currentNesting, $this->inputTokens, $this->inputIndex);
return $result;
}
function processToken($token, $config, $context) {
if (is_array($token)) {
// the original token was overloaded by an injector, time
// to some fancy acrobatics
// $this->inputIndex is decremented so that the entire set gets
// re-processed
array_splice($this->inputTokens, $this->inputIndex--, 1, $token);
// adjust the injector skips based on the array substitution
if ($this->injectors) {
$offset = count($token);
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 += $offset;
}
}
} elseif ($token) {
// regular case
$this->outputTokens[] = $token;
if ($token instanceof HTMLPurifier_Token_Start) {
$this->currentNesting[] = $token;
} elseif ($token instanceof HTMLPurifier_Token_End) {
array_pop($this->currentNesting); // not actually used
}
}
}
}