The NamedNodeMap interface defines a collection
of nodes that may be looked up by name or by namespace URI and local
name. It is unrelated to the java.util.Map
interface. Use getNamedItem( ) to look for and
return a node whose getNodeName( ) method returns
the specified value. Use getNamedItemNS( ) to look
for and return a node whose getNamespaceURI( ) and
getLocalName( ) methods return the specified
values. A NamedNodeMap is a mapping from names to
nodes, and does not order the nodes in any particular way.
Nevertheless, it does impose an arbitrary ordering on the nodes and
allow them to be looked up by index. Use getLength(
) to find out how many nodes are contained in the
NamedNodeMap, and use item( )
to obtain the Node object at a specified index.
If a NamedNodeMap is not read-only, you can use
removeNamedItem( ) and removeNamedItemNS(
) to remove a named node from the map, and you can use
setNamedItem( ) and setNamedItemNS(
) to add a node to the map, mapping to it from its name or
its namespace URI and local name.
NamedNodeMap objects are
"live," which means that they
immediately reflect any changes to the document tree. For example, if
you obtain a NamedNodeMap that represents the
attributes of an element, and then add a new attribute to that
element, the new attribute is automatically available through the
NamedNodeMap: you do not need to obtain a new
NamedNodeMap to get the modified set of
attributes.
NamedNodeMap is returned only by relatively
obscure methods of the DOM API. The most notable use is as the return
value of the getAttributes( ) method of
Node. It is usually easier to work with attributes
through the methods of the Element interface,
however. Two methods of DocumentType also return
read-only NamedNodeMap objects.
public interface NamedNodeMap {
// Public Instance Methods
int getLength( );
Node getNamedItem(String name);
Node getNamedItemNS(String namespaceURI, String localName) throws DOMException;
Node item(int index);
Node removeNamedItem(String name) throws DOMException;
Node removeNamedItemNS(String namespaceURI, String localName) throws DOMException;
Node setNamedItem(Node arg) throws DOMException;
Node setNamedItemNS(Node arg) throws DOMException;
}
