当元素不再具有特定类时，我想调用一个函数

Question

我正在为一个只能使用 javascript 的网站制作插件。我想在 id = "gridview" 的 il 元素不再具有 "hidden" 类时执行代码。感谢您的帮助。

我已经尝试过：

document.getElementById("id="eval_grid_tab"").addEventListener("click", start);  

这是 html

<li id="eval_grid_tab"><a href="#gridview">Tabel</a></li>

<div id="gridview" class="rightsPanel smscTabsPanel hidden" style="height: 795px;">...</div>

Answer 1

为此，您需要使用MutationObserver。它监视 DOM 的更改（例如删除/添加类）并触发回调函数供您以任何您认为合适的方式使用。// Select the node that will be observed for mutationsvar targetNode = document.getElementById('gridview');// Options for the observer (which mutations to observe)var config = { attributes: true };// Callback function to execute when mutations are observedvar callback = function(mutationsList, observer) {&nbsp; &nbsp; for(var mutation of mutationsList) {&nbsp; &nbsp; &nbsp; &nbsp; if (mutation.type == 'attributes') {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Triggers when an attribute like 'class' is modified&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; console.log('The ' + mutation.attributeName + ' attribute was modified.');&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }};// Create an observer instance linked to the callback functionvar observer = new MutationObserver(callback);// Start observing the target node for configured mutationsobserver.observe(targetNode, config);稍后，您可以停止观察observer.disconnect();