Generic Toggle JS for Drupal 7

generic-toggle.html

<a href="#" class="js-dropdown__toggle">Toggle Link</a>
<div class="js-dropdown__wrapper">
  <h3>Toggleable Content</h3>
  <p>Can have other wrappers, but no tag should be between the toggle link and toggle wrapper.</p>
</div>

generic-toggle.js

(function ($, Drupal, window, document, undefined) {
  
  // Generic toggle behavior
  Drupal.behaviors.toggleOpen = {
    attach: function(context, settings) {
      // Only run this stuff once
      $('.js-dropdown__toggle', context).once('js-dropdown--triggered', function(){
        $(this).click(function (e) {
          e.preventDefault();
          $(this).toggleClass('js-is-active');
          $(this).next('.js-dropdown__wrapper').toggleClass('js-is-open');
          $(this).blur();
        });
      });
    }
  };
  
})(jQuery, Drupal, this, this.document);