Nmtokens.php
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<?php
/**
* Validates contents based on NMTOKENS attribute type.
*/
class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
{
/**
* @param string $string
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return bool|string
*/
public function validate($string, $config, $context)
{
$string = trim($string);
// early abort: '' and '0' (strings that convert to false) are invalid
if (!$string) {
return false;
}
$tokens = $this->split($string, $config, $context);
$tokens = $this->filter($tokens, $config, $context);
if (empty($tokens)) {
return false;
}
return implode(' ', $tokens);
}
/**
* Splits a space separated list of tokens into its constituent parts.
* @param string $string
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return array
*/
protected function split($string, $config, $context)
{
// OPTIMIZABLE!
// do the preg_match, capture all subpatterns for reformulation
// we don't support U+00A1 and up codepoints or
// escaping because I don't know how to do that with regexps
// and plus it would complicate optimization efforts (you never
// see that anyway).
$pattern = '/(?:(?<=\s)|\A)' . // look behind for space or string start
'((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)' .
'(?:(?=\s)|\z)/'; // look ahead for space or string end
preg_match_all($pattern, $string, $matches);
return $matches[1];
}
/**
* Template method for removing certain tokens based on arbitrary criteria.
* @note If we wanted to be really functional, we'd do an array_filter
* with a callback. But... we're not.
* @param array $tokens
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return array
*/
protected function filter($tokens, $config, $context)
{
return $tokens;
}
}
// vim: et sw=4 sts=4