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• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

MutationObserverInit dictionary's optional characterDataOldValue property is used to specify whether or not the MutationRecord.oldValue property for DOM mutations should be set to the previous value of text nodes which changed.

If you set the MutationObserverInit.characterData 特性到 true but don't set characterDataOldValue to true as well, the MutationRecord will not include information describing the prior state of the text node's contents.

Character data changes are detectable on any text node, including nodes based on the 文本 , ProcessingInstruction ，和 注释 接口。

句法

var options = {
  characterDataOldValue: true | false
}
					

值

A Boolean value indicating whether or not to set the MutationRecord 's oldValue property to be a string containing the value of the character node's contents prior to the change represented by the mutation record.

By default, only changes to the text of the node specified as the target parameter when you called observe() are monitored. To watch for changes to the text contents of all descendants of target , set the subtree 选项到 true .

若设置 characterDataOldValue to true , characterData is automatically assumed to be true , even if you don't expressly set it as such.

范例

规范

规范	状态	注释
DOM The definition of 'MutationObserverInit.characterDataOldValue' in that specification.	实时标准

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
characterDataOldValue	Chrome 26 26 18 — 26 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 14 注意事项 14 注意事项 Starting in Firefox 36, characterDataOldValue has no default value; previously, its default value was false .	IE 11	Opera 15	Safari 7 7 6 — 7 Prefixed Prefixed Implemented with the vendor prefix: webkit	WebView Android ?	Chrome Android 26 26 18 — 26 Prefixed Prefixed Implemented with the vendor prefix: webkit	Firefox Android 14 注意事项 14 注意事项 Starting in Firefox 36, characterDataOldValue has no default value; previously, its default value was false .	Opera Android 14	Safari iOS 7 7 6 — 7 Prefixed Prefixed Implemented with the vendor prefix: webkit	Samsung Internet Android 1.5 1.5 1.0 — 1.5 Prefixed Prefixed Implemented with the vendor prefix: webkit

图例

完整支持

完整支持

兼容性未知 ?

兼容性未知

见实现注意事项。

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

元数据

• 最后修改： Mar 18, 2019

相关话题

1. MutationObserverInit
2. 特性

   1. attributeFilter
   2. attributeOldValue
   3. 属性
   4. characterData