=head1 NAME

XML::DOM::Attr - An XML attribute in XML::DOM

=head1 DESCRIPTION

XML::DOM::Attr extends L<XML::DOM::Node>.

The Attr nodes built by the XML::DOM::Parser always have one child node

which is a Text node containing the expanded string value (i.e. EntityReferences

are always expanded.) EntityReferences may be added when modifying or creating

a new Document.

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 undef 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.

=head2 METHODS

=over 4

=item getValue

On retrieval, the value of the attribute is returned as a string. 

Character and general entity references are replaced with their values.

=item setValue (str)

DOM Spec: On setting, this creates a Text node with the unparsed contents of the 

string.

=item getName

Returns the name of this attribute.

=back