比如拦截 html 标签的 font-size 样式的更改：
...
<body>
<script>
var observer = new MutationObserver(function (mutations) {
mutations.forEach(function (mutation) {
if (mutation.type === 'attributes' && mutation.attributeName === 'style') {
var target = mutation.target;
var oldStyle = mutation.oldValue;
var newStyle = target.getAttribute('style');
if (target.tagName == "HTML" && newStyle.includes("font-size"))
debugger
}
});
});
var targetNode = document.documentElement;
var config = { attributes: true, attributeOldValue: true, attributeFilter: ['style'] };
observer.observe(targetNode, config);
</script>
...
标签：style,target,更改,js,html,mutation,var From： https://www.cnblogs.com/nanfei/p/17479556.html