The DocumentType.before()
method inserts a set of Node
objects or strings in the children list of the DocumentType
's parent, just before the DocumentType
. Strings are inserted as equivalent Text
nodes.
The DocumentType.before()
method inserts a set of Node
objects or strings in the children list of the DocumentType
's parent, just before the DocumentType
. Strings are inserted as equivalent Text
nodes.
js
before(param1) before(param1, param2) before(param1, param2, /* …, */ paramN)
None (undefined
).
HierarchyRequestError
DOMException
Thrown when the node cannot be inserted at the specified point in the hierarchy.
Comment nodes are valid before doctype declarations but not advisable given they trigger quirks mode in IE. A conditional comment works for IE as well, though:
js
let docType = document.implementation.createDocumentType("html", "", ""); let myDoc = document.implementation.createDocument("", "", docType); docType.before( document.createComment("<!--[if !IE]> conditional comment <![endif]-->"), ); myDoc.childNodes; // NodeList [<!--[if !IE]> conditional comment <![endif]-->, <!DOCTYPE html>]
Specification |
---|
DOM Standard # ref-for-dom-childnode-before① |
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
before |
54 | 17 | 49 | No | 39 | 10 | 54 | 54 | 49 | 41 | 10 | 6.0 |
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/DocumentType/before