[WordPress] ドメイン移行したとき全URLを手っ取り早く変える

class change_URL {
    function change_URL() {
        add_action('get_header', array(&$this, 'get_header'), 1);
        add_action('wp_footer', array(&$this, 'wp_footer'), 99999);
    }
    function replace_URL($content) {
        $old_url = 'http://hoge.example.com/';
        $home_url = trailingslashit(get_home_url('/'));
        return str_replace($old_url, $home_url, $content);
    }
    function get_header(){
        ob_start(array(&$this, 'replace_URL'));
    }
    function wp_footer(){
        ob_end_flush();
    }
}
new change_URL();