Attr in DOM Level 2 Core
The Attr interface represents an attribute in an Element object.
For more information see http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/core.html#ID-637646024.
Inherits from:
Instance Properties
name | type | description |
---|---|---|
attributes | NamedNodeMap | (read only) [from Node] |
childNodes | NodeList | (read only) [from Node] |
firstChild | Node | (read only) [from Node] |
lastChild | Node | (read only) [from Node] |
localName | String | (read only) [from Node] |
name | String | (read only) |
namespaceURI | String | (read only) [from Node] |
nextSibling | Node | (read only) [from Node] |
nodeName | String | (read only) [from Node] |
nodeType | Number | (read only) [from Node] |
nodeValue | String | [from Node] |
ownerDocument | Document | (read only) [from Node] |
ownerElement | Element | (read only) |
parentNode | Node | (read only) [from Node] |
prefix | String | [from Node] |
previousSibling | Node | (read only) [from Node] |
specified | Boolean | (read only) |
value | String |
Instance Methods
name | returns | description |
---|---|---|
addEventListener(type,listener,useCapture) | (none) | [from EventTarget] |
appendChild(newChild) | Node | [from Node] |
cloneNode(deep) | Node | Return a new copy of the node. [from Node] |
dispatchEvent(evt) | Boolean | Dispatches an event to the invoking object. [from EventTarget] |
hasAttributes() | Boolean | [from Node] |
hasChildNodes() | Boolean | [from Node] |
insertBefore(newChild,refChild) | Node | [from Node] |
isSupported(feature,version) | Boolean | [from Node] |
normalize() | (none) | [from Node] |
removeChild(oldChild) | Node | [from Node] |
removeEventListener(type,listener,useCapture) | (none) | [from EventTarget] |
replaceChild(newChild,oldChild) | Node | [from Node] |
Description
Attr
objects inherit the Node
interface, but since they are not actually child nodes of the element they describe, the DOM does not consider them part of the document tree. Thus, the Node
attributes parentNode
, previousSibling
, and nextSibling
have a null
value for Attr
objects. The DOM takes the view that attributes are properties of elements rather than having a separate identity from the elements they are associated with; this should make it more efficient to implement such features as default attributes associated with all elements of a given type. Furthermore, Attr
nodes may not be immediate children of a DocumentFragment
. However, they can be associated with Element
nodes contained within a DocumentFragment
. In short, users and implementors of the DOM need to be aware that Attr
nodes have some things in common with other objects inheriting the Node
interface, but they also are quite distinct.
The attribute's effective value is determined as follows: if this attribute has been explicitly assigned any value, that value is the attribute's effective value; otherwise, if there is a declaration for this attribute, and that declaration includes a default value, then that default value is the attribute's effective value; otherwise, the attribute does not exist on this element in the structure model until it has been explicitly added. Note that the nodeValue
attribute on the Attr
instance can also be used to retrieve the string version of the attribute's value(s).
In XML, where the value of an attribute can contain entity references, the child nodes of the Attr
node may be either Text
or EntityReference
nodes (when these are in use; see the description of EntityReference
for discussion). Because the DOM Core is not aware of attribute types, it treats all attribute values as simple strings, even if the DTD or schema declares them as having tokenized types.
Methods that return a Attr
Arguments that are a Attr
name | in method | of object | description |
---|---|---|---|
newAttr | setAttributeNode(newAttr) | Element | |
newAttr | setAttributeNodeNS(newAttr) | Element | |
oldAttr | removeAttributeNode(oldAttr) | Element |