test/public/themes/simple/tpl/helpers/Highlight.php

<?php

if(!defined('APP_KEY')) { exit('Access Denied'); }

class Helper_Highlight implements Suco_Helper_Interface
{
  protected $_str;
  protected $_keyword;
  
  public static function callback($args)
  {
    return new self($args[0], $args[1]);
  }
  
  public function __construct($str, $keyword)
  {
    $this->_str = $str;
    $this->_keyword = $keyword;
  }
  
  public function __toString()
  {
    $str = $this->_str;
    if (!$str) {
      return '';
    }
    
    if (!empty($this->_keyword)) {
      $keywords = explode(" ", $this->_keyword);
      foreach ($keywords as $keyword) {
        $str = preg_replace('#('.$keyword.')#i', '<font color="red">$1</font>', $str);
      }
    }
    return $str;
  }
}