source: trunk/xpressme_integration_kit/wp-content/themes/xpress_default/blocks/sidebar_block_theme.php

<?php
// Block Version: 1.0
function sidebar_block($options)
{
        $templates = array();
        $templates[] = "sidebar.php";
        $sidebar_path = locate_template($templates, false);
        if (empty($sidebar_path)){ // ktai_style plugin is empty
                $sidebar_path = dirname(dirname(__FILE__)) . "/sidebar.php";
        }
        ob_start();
                require($sidebar_path);
                $output = ob_get_contents();
        ob_end_clean();
        $pattern = '<div\s+id\s*=\s*["\']xpress_sidebar["\']\s*>';
        $output = preg_replace("/".$pattern."/s" , '<div class="xpress_sidebar_block">' , $output);

        $block['sidebar'] = $output;                                                            
        return $block ; 

}

?>