Element: setAttributeNodeNS() method

The setAttributeNodeNS() method of the Element interface adds a new namespaced Attr node to an element.

If you don't need to work with the attribute node (such as cloning from another element) before adding it, you can use the setAttributeNS() method instead.

If you are working with HTML documents and you don't need to specify the requested attribute as being part of a specific namespace, use the setAttribute() method instead.

Syntax

js
setAttributeNodeNS(attributeNode)

Parameters

attributeNode

The Attr node to add to the element.

Return value

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

Examples

js
// <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, you may see 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).

Specifications

Specification
DOM Standard
# dom-element-setattributenodens

Browser compatibility

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See also