executor.js

/**
 * @license MIT http://troopjs.mit-license.org/
 */
define([
  "mu-selector-set/main",
  "jquery"
], function (SelectorSet, $) {
  "use strict";

  /**
   * @class dom.executor
   * @mixin Function
   * @private
   * @static
   * @alias feature.executor
   */

  var UNDEFINED;
  var FALSE = false;
  var LEFT_BUTTON = 0;

  function map (match) {
    return match[1];
  }

  // Use `$.find.matchesSelector` for wider browser support
  SelectorSet.prototype.matchesSelector = $.find.matchesSelector;

  /**
   * @method constructor
   * @inheritdoc core.emitter.executor#constructor
   * @localdoc
   * - Executes handlers synchronously passing each handler `args`.
   * - If a handler returns `false` no more handlers will be executed.
   * - If a handler stops propagation no more handlers will be executed.
   *
   * @return {*} Result from last handler
   */
  return function (event, handlers, args) {
    var result = UNDEFINED;
    var direct = handlers.direct;
    var delegated = handlers.delegated;

    var $event = args[0];
    var $delegate = $event.delegateTarget;
    var $target = $event.target;
    var $document = $target.ownerDocument;
    var $notClick = $event.type !== "click";

    // Bubble the event up the dom if
    // ... this is not a black-holed element (jQuery #13180)
    // ... and this is the left button or it's a not a click event (jQuery #3861)
    var $bubble = $target.nodeType !== UNDEFINED && ($event.button === LEFT_BUTTON || $notClick);


    function reduce (_result, handler) {
      // If immediate propagation is stopped we should just return last _result
      if ($event.isImmediatePropagationStopped()) {
        return _result;
      }

      // If the previous handler return false we should stopPropagation and preventDefault
      if (_result === FALSE) {
        $event.stopPropagation();
        $event.preventDefault();
      }

      return handler.handle(args);
    }

    // Loop ...
    do {
      // Don't process clicks on disabled elements (jQuery #6911, #8165, #11382, #11764)
      if ($target.disabled !== true || $notClick) {
        // Run delegated handlers which match this element
        result = delegated
          .matches($event.currentTarget = $target)
          .map(map)
          .reduce(reduce, result);
      }

      // Bubble if ...
      $bubble = $bubble
        // ... we were not told to stop propagation
        && !$event.isPropagationStopped()
        // ... we are not at the delegate element
        && $target !== $delegate
        // ... we have a parent node
        && ($target = $target.parentNode) !== null
        // ... the new target is not the document
        && $target !== $document;
    }
    // ... while we are still bubbling
    while ($bubble);

    // Run all the direct (non-delegated) handlers of the root element
    if (result !== FALSE) {
      result = direct.reduce(reduce, result);
    }

    return result;
  };
});