<?php

/**
 * Implements special behavior for class attribute (normally NMTOKENS)
 */
class HTMLPurifier_AttrDef_HTML_Class extends HTMLPurifier_AttrDef_HTML_Nmtokens {
	/**
	 *
	 * @param string $string        	
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return bool|string
	 */
	protected function split($string, $config, $context) {
		// really, this twiddle should be lazy loaded
		$name = $config->getDefinition ( 'HTML' )->doctype->name;
		if ($name == "XHTML 1.1" || $name == "XHTML 2.0") {
			return parent::split ( $string, $config, $context );
		} else {
			return preg_split ( '/\s+/', $string );
		}
	}
	
	/**
	 *
	 * @param array $tokens        	
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return array
	 */
	protected function filter($tokens, $config, $context) {
		$allowed = $config->get ( 'Attr.AllowedClasses' );
		$forbidden = $config->get ( 'Attr.ForbiddenClasses' );
		$ret = array ();
		foreach ( $tokens as $token ) {
			if (($allowed === null || isset ( $allowed [$token] )) && ! isset ( $forbidden [$token] ) && 
			// We need this O(n) check because of PHP's array
			// implementation that casts -0 to 0.
			! in_array ( $token, $ret, true )) {
				$ret [] = $token;
			}
		}
		return $ret;
	}
}