gistfile1.php

<?php

interface activity_item {
  public function get_time();
  public function get_message();
  public function get_row(); // assoc array containing time, lang, args
}

class default_activity_item implements activity_item {

  public function __construct($time, $lang, $args) {
    $this->time = $time;
    $this->lang = $lang;
    $this->args = $args;
  }

  public function get_time() {
    return $this->time;
  }

  public function get_message() {
    return vsprintf(registry::$lang[$this->lang], $this->args);
  }

  public function get_row() {
    return array('time' => $this->time, 'lang' => $this->lang, 'args' => serialize($this->args));
  }

}