Example Drupal Behavior

This is an example of a Drupal behavior. Drupal behaviors ensure scripts run on elements updated via AJAX.

I'm not sure about the closing bit. I inherited it from a live system.

(function ($, Drupal, window, document, undefined) {
  /**
   * Seeks out picture elements with the class "has-caption" and uses 
   * the title to create a caption.
   * @type {{attach: Function}}
   */
  Drupal.behaviors.hasCaptions = {
    attach: function (context, settings) {
      $('picture.has-caption').each(function() {
        var title = $('img', $(this)).attr('title');
        if (title) {
          $(this).wrap('<span class="caption-wrapper"></span>')
                 .append('<span class="caption">'+title+'</caption>');
        }
      });
    }
  };

})(jQuery, Drupal,window, document);