<?php
/**
* Validates the attributes of a token. Doesn't manage required attributes
* very well. The only reason we factored this out was because RemoveForeignElements
* also needed it besides ValidateAttributes.
*/
class HTMLPurifier_AttrValidator
{
/**
* Validates the attributes of a token, returning a modified token
* that has valid tokens
* @param $token Reference to token to validate. We require a reference
* because the operation this class performs on the token are
* not atomic, so the context CurrentToken to be updated
* throughout
* @param $config Instance of HTMLPurifier_Config
* @param $context Instance of HTMLPurifier_Context
*/
public function validateToken(&$token, &$config, $context) {
$definition = $config->getHTMLDefinition();
$e =& $context->get('ErrorCollector', true);
// initialize IDAccumulator if necessary
$ok =& $context->get('IDAccumulator', true);
if (!$ok) {
$id_accumulator = HTMLPurifier_IDAccumulator::build($config, $context);
$context->register('IDAccumulator', $id_accumulator);
}
// initialize CurrentToken if necessary
$current_token =& $context->get('CurrentToken', true);
if (!$current_token) $context->register('CurrentToken', $token);
if (
!$token instanceof HTMLPurifier_Token_Start &&
!$token instanceof HTMLPurifier_Token_Empty
) return $token;
// create alias to global definition array, see also $defs
// DEFINITION CALL
$d_defs = $definition->info_global_attr;
// don't update token until the very end, to ensure an atomic update
$attr = $token->attr;
// do global transformations (pre)
// nothing currently utilizes this
foreach ($definition->info_attr_transform_pre as $transform) {
$attr = $transform->transform($o = $attr, $config, $context);
if ($e) {
if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr);
}
}
// do local transformations only applicable to this element (pre)
// ex. <p align="right"> to <p style="text-align:right;">
foreach ($definition->info[$token->name]->attr_transform_pre as $transform) {
$attr = $transform->transform($o = $attr, $config, $context);
if ($e) {
if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr);
}
}
// create alias to this element's attribute definition array, see
// also $d_defs (global attribute definition array)
// DEFINITION CALL
$defs = $definition->info[$token->name]->attr;
$attr_key = false;
$context->register('CurrentAttr', $attr_key);
// iterate through all the attribute keypairs
// Watch out for name collisions: $key has previously been used
foreach ($attr as $attr_key => $value) {
// call the definition
if ( isset($defs[$attr_key]) ) {
// there is a local definition defined
if ($defs[$attr_key] === false) {
// We've explicitly been told not to allow this element.
// This is usually when there's a global definition
// that must be overridden.
// Theoretically speaking, we could have a
// AttrDef_DenyAll, but this is faster!
$result = false;
} else {
// validate according to the element's definition
$result = $defs[$attr_key]->validate(
$value, $config, $context
);
}
} elseif ( isset($d_defs[$attr_key]) ) {
// there is a global definition defined, validate according
// to the global definition
$result = $d_defs[$attr_key]->validate(
$value, $config, $context
);
} else {
// system never heard of the attribute? DELETE!
$result = false;
}
// put the results into effect
if ($result === false || $result === null) {
// this is a generic error message that should replaced
// with more specific ones when possible
if ($e) $e->send(E_ERROR, 'AttrValidator: Attribute removed');
// remove the attribute
unset($attr[$attr_key]);
} elseif (is_string($result)) {
// generally, if a substitution is happening, there
// was some sort of implicit correction going on. We'll
// delegate it to the attribute classes to say exactly what.
// simple substitution
$attr[$attr_key] = $result;
} else {
// nothing happens
}
// we'd also want slightly more complicated substitution
// involving an array as the return value,
// although we're not sure how colliding attributes would
// resolve (certain ones would be completely overriden,
// others would prepend themselves).
}
$context->destroy('CurrentAttr');
// post transforms
// global (error reporting untested)
foreach ($definition->info_attr_transform_post as $transform) {
$attr = $transform->transform($o = $attr, $config, $context);
if ($e) {
if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr);
}
}
// local (error reporting untested)
foreach ($definition->info[$token->name]->attr_transform_post as $transform) {
$attr = $transform->transform($o = $attr, $config, $context);
if ($e) {
if ($attr != $o) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr);
}
}
$token->attr = $attr;
// destroy CurrentToken if we made it ourselves
if (!$current_token) $context->destroy('CurrentToken');
}
}
// vim: et sw=4 sts=4
