Modal dialogs are incredibly useful on websites as they allow the user to do something without having to leave the web page they are on. Drupal 8 now has a Dialog API in core, which greatly reduces the amount of code you need to write to create a modal dialog. Dialogs in Drupal 8 leverage jQuery UI.

In the second part of this series on modal dialogs in Drupal 8, we are going to go a step further from last week by creating the modal in a custom module.