NamedNodeMap: setNamedItemNS() method

The setNamedItemNS() method of the NamedNodeMap interface puts the Attr identified by its name in the map. If there was already an Attr with the same name in the map, it is replaced.

Note: This method is an alias of setNamedItem() you can use them interchangeably.

Syntax

js
setNamedItemNS(attr)

Parameters

attr

The attribute to insert in the map.

Return value

Returns the old attribute if replaced, or null if the attribute is new.

Exceptions

InUseAttributeError DOMException

Thrown if the attribute is still part of another map.

Example

html
<span ob:one="one"></span>
<pre></pre>
js
const parser = new DOMParser();
// ob:one in <span> is not in a namespace, while ob:one in <warning>, is.
const xmlString =
  '<warning ob:one="test" xmlns:ob="http://www.example.com/ob">Beware!</warning>';
const doc = parser.parseFromString(xmlString, "application/xml");

const span = document.querySelector("span");
const pre = document.querySelector("pre");
const warning = doc.querySelector("warning");
const attrMap = span.attributes;

let result = `The '<span>' element initially contains ${attrMap.length} attribute.\n\n`;

result += "We remove `one` from '<span>' and adds it to '<pre>'.\n";
const one = warning.attributes.removeNamedItemNS(
  "http://www.example.com/ob",
  "one",
);
attrMap.setNamedItemNS(one);
result += `The '<span>' element now contains ${span.attributes.length} attributes:\n\n`;
result += "Prefix\tLocal name\tQualified name\n";
result += "=========================================\n";

for (const attr of attrMap) {
  result += `${attr.prefix}\t${attr.localName}\t\t${attr.name}\n`;
}

pre.textContent = result;

Specifications

Specification
DOM Standard
# dom-namednodemap-setnameditemns

Browser compatibility

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