如何在javascript中使用Object.deliverChangeRecords方法

Question

我知道如何使用Object.observe(),和Object.getNotifier(obj).notify或Object.getNotifier(obj).performChange,但我怎么用Object.deliverChangeRecords()

Answer 1

Object.deliverChangeRecords的要点是同步传递到正在侦听突变的函数.

http://www.danyow.net/object-deliverchangerecords/

这是一个运行示例,演示了有和没有的事件序列deliverChangeRecords:

var output = document.getElementById('output');

function runTest(useDeliver) {
  var obj = {};

  output.textContent = '';
 
  function handleChange(records) {
    output.textContent += 'CHANGE DELIVERED\n';
  }
  
  Object.observe(obj, handleChange);
  
  output.textContent += '1\n';
  
  obj.a = 'b';
  
  output.textContent += '2\n';
  
  if (useDeliver) {
    Object.deliverChangeRecords(handleChange);
  }
  
  output.textContent += '3\n';
  
}

<button onclick="runTest(true)">With deliverChangeRecords</button>
<button onclick="runTest(false)">Without deliverChangeRecords</button>
<pre id="output"></pre>