ChildNode.before()

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句法
范例
Polyfill
规范
浏览器兼容性
另请参阅
相关话题

ChildNode.before() method inserts a set of 节点 or DOMString objects in the children list of this ChildNode 's parent, just before this ChildNode . DOMString objects are inserted as equivalent 文本 节点。

句法

[Throws, Unscopable]
void ChildNode.before((Node or DOMString)... nodes);

参数

nodes: 一组 节点 or DOMString objects to insert.

异常

HierarchyRequestError : Node cannot be inserted at the specified point in the hierarchy.

范例

Inserting an element

var parent = document.createElement("div");
var child = document.createElement("p");
parent.appendChild(child);
var span = document.createElement("span");
child.before(span);
console.log(parent.outerHTML);
// "<div><span></span><p></p></div>"

Inserting text

var parent = document.createElement("div");
var child = document.createElement("p");
parent.appendChild(child);
child.before("Text");
console.log(parent.outerHTML);
// "<div>Text<p></p></div>"

Inserting an element and text

var parent = document.createElement("div");
var child = document.createElement("p");
parent.appendChild(child);
var span = document.createElement("span");
child.before(span, "Text");
console.log(parent.outerHTML);
// "<div><span></span>Text<p></p></div>"

`ChildNode.before()` is unscopable

before() method is not scoped into the with statement. See Symbol.unscopables 了解更多信息。

with(node) {
  before("foo");
}
// ReferenceError: before is not defined

Polyfill

You can polyfill the before() method in Internet Explorer 9 and higher with the following code:

// from: https://github.com/jserz/js_piece/blob/master/DOM/ChildNode/before()/before().md
(function (arr) {
  arr.forEach(function (item) {
    if (item.hasOwnProperty('before')) {
      return;
    }
    Object.defineProperty(item, 'before', {
      configurable: true,
      enumerable: true,
      writable: true,
      value: function before() {
        var argArr = Array.prototype.slice.call(arguments),
          docFrag = document.createDocumentFragment();
        argArr.forEach(function (argItem) {
          var isNode = argItem instanceof Node;
          docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
        });
        this.parentNode.insertBefore(docFrag, this);
      }
    });
  });
})([Element.prototype, CharacterData.prototype, DocumentType.prototype]);

规范

规范	状态	注释
DOM The definition of 'ChildNode.before()' 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
`before`	Chrome 54	Edge 17	Firefox 49	IE No	Opera 39	Safari 10	WebView Android 54	Chrome Android 54	Firefox Android 49	Opera Android 41	Safari iOS 10	Samsung Internet Android 6.0

图例

完整支持
不支持
实验。期望将来行为有所改变。

另请参阅

元数据

最后修改： Apr 8, 2020

DOM (文档对象模型)
ChildNode
方法
1. after()
2. before()
3. remove()
4. replaceWith()
实现通过：
DOM 相关页面

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句法

参数

异常

范例