当该跨度值更改时，如何触发事件? [英] How can I trigger an event when this span value changes?

问题描述

当当前页面的股票价格发生变化时，我正在尝试获取控制台日志.

I'm trying to get a console log when the price of the current page's stock changes.

页面: https://www.google.com/finance?q=NASDAQ%3AGOOG&; ei = yvbRVbHSCcKgmAGyu7CoDA

元素ID:#price-panel> div> span> span

Element ID: #price-panel > div > span > span

尝试1: 失败

$("#price-panel div span span").onchange = function() { console.log('change')}

尝试2: 失败

document.getElementById('price-panel').children[0].children[0].onchange = function() { console.log('change')}

builtwith.com表示javascript是"google api"，与google搜索有歧义，因此并没有太大帮助.

builtwith.com says the javascript is the "google api" which is ambiguous to google searches so that didn't help much.

该元素更改时，我可以观看什么事件来找出?

What event can I watch to find out when this element is change?

推荐答案

来自 Dom事件尝试收听< span> 中的文本更改，则可以使用 DOMCharacterDataModified .

From Dom Events as your try to listen to text changes in <span> you may be able to use DOMCharacterDataModified.

或者您可以使用 MutationObserver 来捕获变化.

Or you can use MutationObserver to capture the changes.

var span = document.querySelector('#test');
var text = document.createTextNode('tttt');

// This may be deprecated.
span.addEventListener('DOMCharacterDataModified', function() {
    alert('span text changed to: ' + this.innerHTML);
});

// You may use MutationObserver instead.
var mutateObserver = new MutationObserver(function(records) {
  console.log(records);
});
mutateObserver.observe(span, {
  childList: true,                                 // capture child add/remove on target element.
  characterData: true,                     // capture text changes on target element
  subtree: true,                                   // capture childs changes too
  characterDataOldValue: true  // keep of prev value
});

setTimeout(function() {
  span.innerHTML ='SSSS';
}, 2000);

setTimeout(function() {
  span.appendChild(text);
}, 3000);

setTimeout(function() {
  text.data = '3123';
}, 4000);

<span id="test">This is a span</span>

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