The getAttributeNS()
method of the Element
interface returns the string value of the attribute with the specified namespace and name. If the named attribute does not exist, the value returned will either be null
or ""
(the empty string); see Notes for details.
Syntax
attrVal = element.getAttributeNS(namespace, name)
Parameters
namespace
- The namespace in which to look for the specified attribute.
name
- The name of the attribute to look for.
Return value
The string value of the specified attribute. If the attribute doesn't exist, the result is null
.
Note: Earlier versions of the DOM specification had this method described as returning an empty string for non-existent attributes, but it was not typically implemented this way since null makes more sense. The DOM4 specification now says this method should return null for non-existent attributes.
Examples
The following SVG document reads the value of the foo
attribute in a custom namespace.
<svg xmlns="http://www.w3.org/2000/svg"
xmlns:test="http://www.example.com/2014/test" width="40" height="40">
<circle id="target" cx="12" cy="12" r="10" stroke="#444"
stroke-width="2" fill="none" test:foo="Hello namespaced attribute!"/>
<script type="text/javascript">
var ns = 'http://www.example.com/2014/test';
var circle = document.getElementById( 'target' );
console.log( 'attribute test:foo: "' + circle.getAttributeNS( ns, 'foo' ) + '"' );
</script>
</svg>
In an HTML5 document the attribute has to be accessed with test:foo
since namespaces are not supported.
<!DOCTYPE html>
<html>
<body>
<svg xmlns="http://www.w3.org/2000/svg"
xmlns:test="http://www.example.com/2014/test" width="40" height="40">
<circle id="target" cx="12" cy="12" r="10" stroke="#444" stroke-width="2"
fill="none" test:foo="Foo value"/>
</svg>
<script type="text/javascript">
var ns = 'http://www.example.com/2014/test';
var circle = document.getElementById( 'target' );
console.log('Attribute value: ' + circle.getAttribute('test:foo'));
</script>
</body>
</html>
Notes
Namespaces are only supported in XML documents. HTML5 documents have to use getAttribute()
instead.
getAttributeNS()
differs from getAttribute()
in that it allows you to further specify the requested attribute as being part of a particular namespace, as in the example above, where the attribute is part of the fictional "specialspace" namespace on Mozilla.
Prior to the DOM4 specification, this method was specified to return an empty string rather than null for non-existent attributes. However, most browsers instead returned null. Starting with DOM4, the specification now says to return null. However, some older browsers return an empty string. For that reason, you should use hasAttributeNS()
to check for an attribute's existence prior to calling getAttributeNS()
if it is possible that the requested attribute does not exist on the specified element.
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 | Status | Comment |
---|---|---|
DOMThe definition of 'Element.getAttributeNS()' in that specification. | Living Standard | |
Document Object Model (DOM) Level 3 Core SpecificationThe definition of 'Element.getAttributeNS()' in that specification. | Obsolete | Specifies that a NOT_SUPPORTED_ERR exception is thrown if the UA does not support the "XML" feature. Also specifies that null must be passed to have no namespace.
|
Document Object Model (DOM) Level 2 Core SpecificationThe definition of 'Element.getAttributeNS()' in that specification. | Obsolete | Initial definition |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
getAttributeNS
|
Chrome
Full support Yes |
Edge
Full support 12 |
Firefox Full support Yes Full support Yes Notes' Starting in Firefox 13, |
IE
Full support Yes |
Opera
Full support Yes |
Safari
Full support 6 |
WebView Android
Full support Yes |
Chrome Android
Full support Yes |
Firefox Android
Full support Yes |
Opera Android
Full support Yes |
Safari iOS
Full support Yes |
Samsung Internet Android
Full support Yes |
Legend
- Full support
- Full support
- See implementation notes.'
- See implementation notes.
See also
Element.getAttributeNS() by Mozilla Contributors is licensed under CC-BY-SA 2.5.