MutationObserver
MutationObserver 介面提供了監視 DOM 樹變化的機制。它是為了取代舊的 Mutation Events 功能而設計的,後者是 DOM3 Events 規範的一部分。
建構函式
MutationObserver()-
建立一個新的
MutationObserver例項並返回,當 DOM 發生變化時,它會呼叫指定的 callback 函式。
例項方法
disconnect()-
停止
MutationObserver例項接收後續通知,直到(且除非)再次呼叫observe()方法。 observe()-
配置
MutationObserver,使其在發生與給定選項匹配的 DOM 更改時,開始透過其 callback 函式接收通知。 takeRecords()-
從
MutationObserver的通知佇列中移除所有待處理的通知,並以MutationRecord物件的Array形式返回它們。
示例
以下示例改編自 這篇部落格文章。
js
// Select the node that will be observed for mutations
const targetNode = document.getElementById("some-id");
// Options for the observer (which mutations to observe)
const config = { attributes: true, childList: true, subtree: true };
// Callback function to execute when mutations are observed
const callback = (mutationList, observer) => {
for (const mutation of mutationList) {
if (mutation.type === "childList") {
console.log("A child node has been added or removed.");
} else if (mutation.type === "attributes") {
console.log(`The ${mutation.attributeName} attribute was modified.`);
}
}
};
// Create an observer instance linked to the callback function
const observer = new MutationObserver(callback);
// Start observing the target node for configured mutations
observer.observe(targetNode, config);
// Later, you can stop observing
observer.disconnect();
規範
| 規範 |
|---|
| DOM # interface-mutationobserver |
瀏覽器相容性
載入中…