谷歌Dart: IListElement的变更事件

Question

我想知道您是否可以监听UListElement的元素何时发生了更改(即添加或删除了LIElement )？

UListElement toDoList = query('#to-do-list');
LIElement newToDo = new LIElement();
newToDo.text = "New Task";
toDoList.elements.add(newToDo);
// how do I execute some code once the newToDo has been added to the toDoList?

我假设elements.add()是异步的，因为我有ActionScript背景。这是一个有效的假设吗？

Answer 1

void setMutationObserver(Element element){
  new MutationObserver(mutationHandler)
    .observe(element, subtree: true, childList: true, attributes: false);
}

void mutationHandler(List<MutationRecord> mutations,
                    MutationObserver observer){
  for (final MutationRecord r in mutations){
    r.addedNodes.forEach((node){
      // do stuff here
    });

    r.removedNodes.forEach((node){
      // or here
    });
  }
}

Answer 2

element.elements.add(otherElement)是同步的，相当于Javascript中的element.appendChild(otherElement) (即，DOM Level 2 Core : appendChild)。

Answer 3

您可能还会对我们与MDV的合作感兴趣：

• http://blog.sethladd.com/2012/11/your-first-input-field-binding-with-web.html
• http://blog.sethladd.com/2012/11/your-first-model-driven-view-with-dart.html