class myLessUtils { public static function foobar(ILess_FunctionRegistry $registry, ILess_Node $color = null) { // what can you do here, look to FunctionRegistry.php if ($color instanceof ILess_Node_Color) { return new ILess_Node_Anonymous('"Color is here"'); } return new ILess_Node_Anonymous('"Foobar is here!"'); } } try { $cacheDir = dirname(__FILE__) . '/cache'; $parser = new ILess_Parser(); // adds a function with an alias: fb $parser->addFunction('foobar', array('myLessUtils', 'foobar'), array('fb')); $parser->parseString(' @color: red; #head { color: foobar(@color); font-size: fb(); }'); } catch (Exception $e) { @header('HTTP/1.0 500 Internal Server Error'); echo $e; exit; } $cssContent = $parser->getCSS(); file_put_contents($cacheDir . '/function.css', $cssContent); $css = 'cache/function.css'; $example = 'custom function';