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This type represents a DOM element's attribute as an object. In most DOM methods, you will probably directly retrieve the attribute as a string (e.g., Element.getAttribute()
, but certain functions (e.g., Element.getAttributeNode()
) or means of iterating give Attr
types.
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Attr
inherited from Node
. This is no longer the case in DOM4. In order to bring the implementation of Attr
up to specification, work is underway to change it to no longer inherit from Node
. You should not be using any Node
properties or methods on Attr
objects.Starting in Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4), the ones that are going to be removed output warning messages to the console. You should revise your code accordingly. See Deprecated properties and methods for a complete list.
Properties
name
Read only- The attribute's name.
namespaceURI
Read only- A
DOMString
representing the namespace URI of the attribute, ornull
if there is no namespace. localName
Read only- A
DOMString
representing the local part of the qualified name of the attribute. prefix
Read only- A
DOMString
representing the namespace prefix of the attribute, ornull
if no prefix is specified. ownerElement
Read only-
The element holding the attribute.
Note: DOM Level 4 removed this property. The assumption was that since you get an
Attr
object from anElement
, you should already know the associated element.
As that doesn't hold true in cases likeAttr
objects being returned byDocument.evaluate
, the DOM Living Standard reintroduced the property.Gecko outputs a deprecation note starting from Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4). This note was removed again in Gecko 49.0 (Firefox 49.0 / Thunderbird 49.0 / SeaMonkey 2.46).
specified
Read only- This property always returns
true
. Originally, it returnedtrue
if the attribute was explicitly specified in the source code or by a script, andfalse
if its value came from the default one defined in the document's DTD. value
- The attribute's value.
Note: DOM Level 3 defined namespaceURI
, localName
and prefix
on the Node
interface. In DOM4 they were moved to Attr
.
This change is implemented in Chrome since version 46.0 and Firefox since version 48.0.
Deprecated properties and methods
The following properties have been deprecated. Where available, the appropriate replacement is provided.
attributes
- This property now always returns
NULL
. childNodes
Obsolete since Gecko 14- This property now always returns and empty
NodeList
. firstChild
Obsolete since Gecko 14- This property now always returns
NULL
. isId
Read only- Indicates whether the attribute is an "ID attribute". An "ID attribute" being an attribute which value is expected to be unique across a DOM Document. In HTML DOM, "id" is the only ID attribute, but XML documents could define others. Whether or not an attribute is unique is often determined by a DTD or other schema description.
lastChild
Obsolete since Gecko 14- This property now always returns
NULL
. nextSibling
- This property now always returns
NULL
. nodeName
- Use
Attr.name
instead. nodeType
- This property now always returns 2 (
ATTRIBUTE_NODE
). nodeValue
- Use
Attr.value
instead. ownerDocument
- You shouldn't have been using this in the first place, so you probably don't care that this is going away.
parentNode
- This property now always returns
NULL
. previousSibling
- This property now always returns
NULL
. schemaTypeInfo
Read only- The type information associated with this attribute. While the type information contained in this attribute is guaranteed to be correct after loading the document or invoking
Document.normalizeDocument
, this property may not be reliable if the node was moved. specified
- This property now always returns
true
. textContent
- Use
Attr.value
instead.
The following methods have been deprecated:
appendChild()
Obsolete since Gecko 14- Modify the value of
Attr.value
instead. cloneNode()
- You shouldn't have been using this in the first place, so you probably don't care that this is going away.
createAttribute()
- Use
Element.setAttribute()
instead. createAttributeNS()
- Use
Element.setAttributeNS()
instead. getAttributeNode()
- Use
Element.getAttribute()
instead. getAttributeNodeNS()
- Use
Element.getAttributeNS()
instead. hasAttributes()
Obsolete since Gecko 21.0- This method now always returns false.
hasChildNodes()
- This method now always returns false.
insertBefore()
- Modify the value of
Attr.value
instead. isSupported()
- You shouldn't have been using this in the first place, so you probably don't care that this is going away.
isEqualNode()
- You shouldn't have been using this in the first place, so you probably don't care that this is going away.
normalize()
- You shouldn't have been using this in the first place, so you probably don't care that this is going away.
removeAttributeNode()
- Use
Element.removeAttribute()
instead. removeChild()
Obsolete since Gecko 14- Modify the value of
Attr.value
instead. replaceChild()
Obsolete since Gecko 14- Modify the value of
Attr.value
instead. setAttributeNode()
- Use
Element.setAttribute()
instead. setAttributeNodeNS()
- Use
Element.setAttributeNS()
instead.
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'Attr' in that specification. |
Living Standard | Added ownerElement property back |
DOM4 The definition of 'Attr' in that specification. |
Recommendation | Moved namespaceURI , prefix and localName from Node to this API and removed ownerElement , schemaTypeInfo and isId . |
Document Object Model (DOM) Level 3 Core Specification The definition of 'Attr' in that specification. |
Recommendation | Initial definition |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes)[1] | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) [1] | (Yes) | (Yes) | (Yes) | (Yes) | (Yes)[1] |
[1] As of Chrome 45, this property no longer inherits from Node.