ModelBundle/Helper/SuppressSpecialCharacterHelper.php
public function transform($input, $authorizeSpecial = array())
    {
        $element = trim($input);
        $element = str_replace(' ', '_', $element);
        $element = htmlentities($element, ENT_NOQUOTES, 'UTF-8');
        $accents = '/&([A-Za-z]{1,2})(grave|acute|circ|cedil|uml|lig|tilde);/';
        $element = preg_replace($accents, '$1', $element);
        $authorizeSpecial = join('',$authorizeSpecial);
        $element = preg_replace('/[^-a-z_A-Z0-9'.$authorizeSpecial.']+/', '', $element);

        return strtolower($element);
    }
public function transform($input, $authorizeSpecial = array())
    {
        $element = trim($input);
        $element = str_replace(' ', '_', $element);
        $element = htmlentities($element, ENT_NOQUOTES, 'UTF-8');
        $accents = '/&([A-Za-z]{1,2})(grave|acute|circ|cedil|uml|lig|tilde);/';
        $element = preg_replace($accents, '$1', $element);
        $authorizeSpecial = join('',$authorizeSpecial);
        $element = preg_replace('/[^-a-z_A-Z0-9'.$authorizeSpecial.']+/', '', $element);

        return strtolower($element);
    }
@param string $input
@param array  $authorizeSpecial

@return string