Element: setAttributeNodeNS() method

setAttributeNodeNS adds a new namespaced attribute node to an element.

Syntax

setAttributeNodeNS(attributeNode)

Parameters

attributeNode is an Attr node.

Return value

The replaced attribute node, if any, returned by this function.

Examples

// <div id="one" xmlns:myNS="http://www.mozilla.org/ns/specialspace"
//            myNS:special-align="utterleft">one</div>
// <div id="two">two</div>

const myns = "http://www.mozilla.org/ns/specialspace";
const d1 = document.getElementById("one");
const d2 = document.getElementById("two");
const a = d1.getAttributeNodeNS(myns, "special-align");
d2.setAttributeNodeNS(a.cloneNode(true));
alert(d2.attributes[1].value); // returns: `utterleft'

Notes

If the specified attribute already exists on the element, then that attribute is replaced with the new one and the replaced one is returned.

Note that if you try to set without cloning the node, Mozilla gives an NS_ERROR_DOM_INUSE_ATTRIBUTE_ERR "Attribute already in use" error, as the DOM requires cloning for Attr to be reused (unlike other Nodes which can be moved).

DOM methods dealing with element's attributes:

Not namespace-aware, most commonly used methods	Namespace-aware variants (DOM Level 2)	DOM Level 1 methods for dealing with `Attr` nodes directly (seldom used)	DOM Level 2 namespace-aware methods for dealing with `Attr` nodes directly (seldom used)
`setAttribute` (DOM 1)	`setAttributeNS`	`setAttributeNode`	`setAttributeNodeNS`
`getAttribute` (DOM 1)	`getAttributeNS`	`getAttributeNode`	`getAttributeNodeNS`
`hasAttribute` (DOM 2)	`hasAttributeNS`	-	-
`removeAttribute` (DOM 1)	`removeAttributeNS`	`removeAttributeNode`	-

Specifications

Specification
DOM Standard # dom-element-setattributenodens

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`setAttributeNodeNS`	1	12 Returns a `ClientRectList` with `ClientRect` objects (which do not contain `x` and `y` properties) instead of `DOMRect` objects.	1	9 Returns a `ClientRectList` with `ClientRect` objects (which do not contain `x` and `y` properties) instead of `DOMRect` objects.	≤12.1	1	4.4	18	4	≤12.1	1	1.0

Docs

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