检测DOM元素顺序的变化 [英] Detect changes in DOM elements order

问题描述

我有以下代码：

<div>
  <span>Random text</span> 
  <span style="color: red">Random text</span>
</div>

并使用代码，我有50％的机会更改div内的元素的顺序。$ {

$ b

and, using code, I have a 50% chance of changing the order of the elements inside the div.

$(document).ready(function() {
  var initial = $("div"); //This might not be ok

  if (new Date() % 2) //50% chance to randomize order 
    randomizeOrder();

  var after = $("div"); //Also this might not be ok
  //Detect if the order of spans changed
  if (after != initial) //Definitely won't work
    console.log("Order changed");
})

function randomizeOrder() {
  var lastElement = $("div span").last();
  $(lastElement).insertBefore($("div span").first());
}

此示例过于简单。订购是由用户完成的，使用第三方库，不会告诉我，如果订单实际上改变，只是告诉我什么时候开始&完成。

This example is oversimplified. The ordering is done by the user using a 3rd party library which won't tell me if the order actually changed, just tell me when it started & finished.

如何检测DOM元素的顺序是否实际改变？我内部的信息不能被使用，因为它可以是完全一样的，如在例子中。

How can I detect if the order of the DOM elements actually changed? The information I have inside them cannot be used, as it can be exactly the same, as in the example.

小提琴

推荐答案

如果要检查DOM中的更改，可以使用 MutationObserver ：

If you want to check for changes in the DOM you can use the MutationObserver:

$(document).ready(function() {
  var initial = $("div"); //This might not be ok

  if (new Date() % 2) {
    randomizeOrder();
  }
  
});

function randomizeOrder() {
  var lastElement = $("div span").last();
  $(lastElement).insertBefore($("div span").first());
}

var target = document.getElementById('id1');

// create an observer instance
var observer = new MutationObserver(function(mutations) {
  var changed = false;
  mutations.forEach(function(mutation) {
    // You can check the actual changes here
  });
  console.log('Dom Changed');
});

// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true };

// pass in the target node, as well as the observer options
observer.observe(target, config);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="id1">
  <span>Random text</span> 
  <span style="color: red">Random text</span>
</div>

MutationObserver 使您能够检查特定元素中的DOM更改，而不需要更改DOM的代码。

The MutationObserver gives you the ability to check for DOM changes in a specific element, without any requirement regarding the code the changes the DOM.

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