setNamedItemNS (W3C DOM Core method)

Version Depr. Static
DOM2 No No
Browser support (more…)
IE7 FF1.5+ SA1.3+ OP9+
None Buggy Buggy Buggy


var attrs = document.documentElement.attributes;

var lang = document.createAttributeNS
	('', 'lang');
lang.nodeValue = 'en-au-tas';


The example above saves the attributes collection of the documentElement, then creates a new attribute node in the XML namespace, with the name lang and the value en-au-tas, and assigns it to that collection.

If a node with that local name and namespace already existed in the collection then it will be overwritten with the new value; otherwise a new item will be added, and therefore a new attribute node will apply to the original element.


node (Node) required

The node to add to the map. The node can subsequently be retrieved using its localName and namespaceURI.


Add a specified namespaced node to a NamedNodeMap.

If a node with that local name and namespace URI already exists in the map, it will be replaced. For certain kinds of node — where all instances have the same name (such as #text or #comment) — it's not possible to store more than one instance of such a node within a single node map, because the names would clash. The DOM specification considers this preferable to implementing aliases.

The useage and behavior of this method is identical to setNamedItem except that the local name and namespace URI are both taken into account when determining whether an existing attribute should be replaced, rather than just the name.

Return value

If the new node replaces an existing node, the previously existing node is returned; otherwise null is returned.


Internet Explorer Firefox Safari Opera
5.5 6.0 7.0 1.5 2.0 3.0 1.3 2.0 3.0 9.0 9.5
None None None Buggy Buggy Buggy Buggy Buggy Buggy Buggy Buggy

Internet Explorer doesn't implement this method (it returns undefined).

In Safari an empty-string namespace is treated the same as a null namespace (ie. it's taken to mean no namespace, when it should be treated as a real namespace URI); conversely Opera only understands an empty string to mean no namespace, it doesn't understand null; Firefox understands null but will throw a DOMException over an empty string (code 14: NAMESPACE_ERR).

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