Example Twitter addon using KRL, subscribing to the stream_item_clicked event

twitter-addon-stream-item-clicked.krl

ruleset a60x436 {
  meta {
    name "example-staf-app"
    description <<
      example-staf-app
    >>
    author "Mike Grace"
    logging on
  }

  rule parity_of_users_twitter_id {
    select when web stream_item_clicked
    pre {
      userId = event:param("userId");
      target = event:param("target");
      lastDigit = "#{userId}".replace(re/.*(.$)/,"$1");
      evenDigit = "#{lastDigit}".replace(re/[0,2,4,6,8]/,"even");
      parity = (evenDigit eq "even") => "even" | "odd";
      parityNotice =<<
        <p>This users Twitter ID is <b>#{parity}</b></p>
      >>;
    }
    {
      append(target, parityNotice);
      emit <|
        checkin("a60x436", target);
      |>;
    }
  }

}