org.w3c.dom.Attr Maven / Gradle / Ivy
// Copyright (c) 1998 by W3C
//
// DOM is a trademark of W3C
// The DOM level 1 specification, from which this
// source is derived, is copyright by W3C.
// See: http://www.w3.org/TR/REC-DOM-Level-1/
//
package org.w3c.dom;
/**
The Attr interface represents an attribute in an Element object.
Typically the allowable values for the attribute are defined in a document
type definition.
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 provide a representation in
which entity references are not expanded. These child nodes may be either
Text or EntityReference nodes. Because the
attribute type may be unknown, there are no tokenized attribute values.
Property Summary
name
getName
Returns the name of this attribute.
specified
getSpecified
If this attribute was explicitly given a value in the original
document, this is true; otherwise, it is false.
Note that the implementation is in charge of this attribute, not the
user. If the user changes the value of the attribute (even if it ends up
having the same value as the default value) then the specified
flag is automatically flipped to true. To re-specify the
attribute as the default value from the DTD, the user must delete the
attribute. The implementation will then make a new attribute available
with specified set to false and the default value
(if one exists).
In summary:
If the attribute has an assigned value in the document then
specified is true, and the value is the
assigned value.
If the attribute has no assigned value in the document and has
a default value in the DTD, then specified is false,
and the value is the default value in the DTD.
If the attribute has no assigned value in the document and has
a value of #IMPLIED in the DTD, then the attribute does not appear
in the structure model of the document.
value
getValue
setValue
On retrieval, the value of the attribute is returned as a
string. Character and general entity references are replaced with their
values.
On setting, this creates a Text node with the unparsed
contents of the string.
*/
public interface Attr
extends Node
{
/**
* Returns the value of the name property.
*/
String getName ();
/**
* Returns the value of the specified property.
*/
boolean getSpecified ();
/** Assigns the value of the value property.
*/
void setValue (String value);
/**
* Returns the value of the value property.
*/
String getValue ();
}