Add select event to autocomplete element (d.org/node/365241)

[herbdool]

This matches this issue https://www.drupal.org/node/365241 that was merged into Drupal 7 (11 years ago).

See https://drupal.stackexchange.com/questions/138625/whats-the-event-triggered-after-an-autocomplete-has-run-and-how-to-retrieve-the for an example use case.

[herbdool]

This can be tested by adding an autocomplete field to a form, such as an entity reference field with the autocomplete widget. Then attach a JS file (perhaps with backdrop_add_js()) containing the following:

(function ($) {
  Backdrop.behaviors.autocompleteSupervisor = {
    attach: function (context) {
      $("input.form-autocomplete", context).on('autocompleteSelect', function (event, node) {
        console.log($(this).val()); // user-entered string
        console.log($(node).data('autocompleteValue')); // key of selected item
        console.log($(node).text()); // label of selected item
      });
    }
  };
})(jQuery);

[herbdool]

I've made this just a task since it's been in Drupal 7 for more than a decade.