Node.isConnected

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句法
范例
Polyfill
规范
浏览器兼容性
相关话题

isConnected 只读特性在 节点 interface returns a boolean indicating whether the node is connected (directly or indirectly) to the context object, for example the Document object in the case of the normal DOM, or the ShadowRoot in the case of a shadow DOM.

句法

var isItConnected = nodeObjectInstance.isConnected

返回值

A 布尔 也就是 true if the node is connected to its relevant context object, and false 若不。

范例

Standard DOM

A standard DOM example:

let test = document.createElement('p');
console.log(test.isConnected); // Returns false
document.body.appendChild(test);
console.log(test.isConnected); // Returns true

Shadow DOM

A shadow DOM example:

// Create a shadow root
var shadow = this.attachShadow({mode: 'open'});
// Create some CSS to apply to the shadow dom
var style = document.createElement('style');
console.log(style.isConnected); // returns false
style.textContent = `
.wrapper {
  position: relative;
}
.info {
  font-size: 0.8rem;
  width: 200px;
  display: inline-block;
  border: 1px solid black;
  padding: 10px;
  background: white;
  border-radius: 10px;
  opacity: 0;
  transition: 0.6s all;
  positions: absolute;
  bottom: 20px;
  left: 10px;
  z-index: 3
}
`;
// Attach the created style element to the shadow dom
shadow.appendChild(style);
console.log(style.isConnected); // Returns true

Polyfill

Node.isConnected can be polyfilled with the following code for IE10 and EdgeHTML:

/*
 * Node.isConnected polyfill for IE and EdgeHTML
 * 2020-02-04
 *
 * By Eli Grey, https://eligrey.com
 * Public domain.
 * NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
 */
if (!('isConnected' in Node.prototype)) {
  Object.defineProperty(Node.prototype, 'isConnected', {
    get() {
      return (
        !this.ownerDocument ||
        !(
          this.ownerDocument.compareDocumentPosition(this) &
          this.DOCUMENT_POSITION_DISCONNECTED
        )
      );
    },
  });
}

规范

规范	状态	注释
DOM The definition of 'isConnected' in that specification.	实时标准	初始定义。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`isConnected`	Chrome 51	Edge 79	Firefox 53	IE 不支持 No	Opera 38	Safari 10.1	WebView Android 51	Chrome Android 51	Firefox Android 45	Opera Android 41	Safari iOS 10.3	Samsung Internet Android 6.0

图例

完整支持
不支持

元数据

最后修改： May 21, 2020

DOM (文档对象模型)
节点
特性
1. baseURI
2. baseURIObject
3. childNodes
4. firstChild
5. isConnected
6. lastChild
7. ~~localName~~
8. ~~namespaceURI~~
9. nextSibling
10. nodeName
11. ~~nodePrincipal~~
12. nodeType
13. nodeValue
14. outerText
15. ownerDocument
16. parentElement
17. parentNode
18. ~~prefix~~
19. previousSibling
20. ~~rootNode~~
21. textContent
方法
继承：
1. EventTarget
DOM 相关页面

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句法

返回值

范例

Standard DOM

Shadow DOM

Polyfill

规范

浏览器兼容性

图例

相关话题