Function areAnimationsAllowed

test/angular/1.4/angular-animate.js:2731–2814

* This fn returns false if any of the following is true: * a) animations on any parent element are disabled, and animations on the element aren't explicitly allowed * b) a parent element has an ongoing structural animation, and animateChildren is false * c) the element is not a child

(element, parentElement, event)

     * d) the element is not a child of the $rootElement
     */
    function areAnimationsAllowed(element, parentElement, event) {
      var bodyElement = jqLite(rawDocument.body);
      var bodyElementDetected = isMatchingElement(element, bodyElement) || element[0].nodeName === 'HTML';
      var rootElementDetected = isMatchingElement(element, $rootElement);
      var parentAnimationDetected = false;
      var animateChildren;
      var elementDisabled = disabledElementsLookup.get(getDomNode(element));

      var parentHost = jqLite.data(element[0], NG_ANIMATE_PIN_DATA);
      if (parentHost) {
        parentElement = parentHost;
      }

      parentElement = getDomNode(parentElement);

      while (parentElement) {
        if (!rootElementDetected) {
          // angular doesn't want to attempt to animate elements outside of the application
          // therefore we need to ensure that the rootElement is an ancestor of the current element
          rootElementDetected = isMatchingElement(parentElement, $rootElement);
        }

        if (parentElement.nodeType !== ELEMENT_NODE) {
          // no point in inspecting the #document element
          break;
        }

        var details = activeAnimationsLookup.get(parentElement) || {};
        // either an enter, leave or move animation will commence
        // therefore we can't allow any animations to take place
        // but if a parent animation is class-based then that's ok
        if (!parentAnimationDetected) {
          var parentElementDisabled = disabledElementsLookup.get(parentElement);

          if (parentElementDisabled === true && elementDisabled !== false) {
            // disable animations if the user hasn't explicitly enabled animations on the
            // current element
            elementDisabled = true;
            // element is disabled via parent element, no need to check anything else
            break;
          } else if (parentElementDisabled === false) {
            elementDisabled = false;
          }
          parentAnimationDetected = details.structural;
        }

        if (isUndefined(animateChildren) || animateChildren === true) {
          var value = jqLite.data(parentElement, NG_ANIMATE_CHILDREN_DATA);
          if (isDefined(value)) {
            animateChildren = value;
          }
        }

        // there is no need to continue traversing at this point
        if (parentAnimationDetected && animateChildren === false) break;

        if (!bodyElementDetected) {
          // we also need to ensure that the element is or will be a part of the body element