Function mergeAnimationDetails

test/angular/1.4/angular-animate.js:226–265

(element, oldAnimation, newAnimation)

}

function mergeAnimationDetails(element, oldAnimation, newAnimation) {
  var target = oldAnimation.options || {};
  var newOptions = newAnimation.options || {};

  var toAdd = (target.addClass || '') + ' ' + (newOptions.addClass || '');
  var toRemove = (target.removeClass || '') + ' ' + (newOptions.removeClass || '');
  var classes = resolveElementClasses(element.attr('class'), toAdd, toRemove);

  if (newOptions.preparationClasses) {
    target.preparationClasses = concatWithSpace(newOptions.preparationClasses, target.preparationClasses);
    delete newOptions.preparationClasses;
  }

  // noop is basically when there is no callback; otherwise something has been set
  var realDomOperation = target.domOperation !== noop ? target.domOperation : null;

  extend(target, newOptions);

  // TODO(matsko or sreeramu): proper fix is to maintain all animation callback in array and call at last,but now only leave has the callback so no issue with this.
  if (realDomOperation) {
    target.domOperation = realDomOperation;
  }

  if (classes.addClass) {
    target.addClass = classes.addClass;
  } else {
    target.addClass = null;
  }

  if (classes.removeClass) {
    target.removeClass = classes.removeClass;
  } else {
    target.removeClass = null;
  }

  oldAnimation.addClass = target.addClass;
  oldAnimation.removeClass = target.removeClass;

  return target;
}

function resolveElementClasses(existing, toAdd, toRemove) {
  var ADD_CLASS = 1;