NamedNodeMap (Org.W3C.DOM Package)

Objects implementing the NamedNodeMap interface are used to represent collections of nodes that can be accessed by name. NamedNodeMap does not inherit from NodeList; NamedNodeMaps are not maintained in any particular order. Objects contained in an object implementing NamedNodeMap may also be accessed by an ordinal index, but this is simply to allow convenient enumeration of the contents of a NamedNodeMap, and does not imply that the DOM specifies an order to these Nodes. .

See the following for methods.

getLength

The number of nodes in the map. The range of valid child node indices is 0 to length-1 inclusive.

Syntax:

public int getLength()

getNamedItem

Retrieves a node specified by name.

Syntax:

public Node getNamedItem(java.lang.String name)

Parameters:

name - Name of a node to retrieve.

Return value:

A Node (of any type) with the specified name, or null if the specified name did not identify any node in the map.

item

Returns the nth item in the map. If index (n) is greater than or equal to the number of nodes in the map, this returns null.

Syntax:

public Node item(int index)

Parameters:

index - Index into the map.

Return value:

The node at the nth position in the NamedNodeMap, or null if that is not a valid index.

removeNamedItem

Removes a node specified by name. If the removed node is an Attr with a default value it is immediately replaced.

Syntax:

public Node removeNamedItem(java.lang.String name)
           throws DOMException

Parameters:

name - The name of a node to remove.

Return value:

The node removed from the map or null if no node with such a name exists.

Throws:

DOMException - NOT_FOUND_ERR: Raised if there is no node named name in the map.

setNamedItem

Adds a node using its nodeName attribute.

As the nodeName attribute is used to derive the name which the node must be stored under, multiple nodes of certain types (those that have a "special" string value) cannot be stored as the names would clash. This is seen as preferable to allowing nodes to be given an alias.

Syntax:

public Node setNamedItem(Node arg)
        throws DOMException

Parameters:

arg - A node to store in a named node map. The node will later be accessible using the value of the nodeName attribute of the node. If a node with that name is already present in the map, it is replaced by the new one.

Return value:

If the new Node replaces an existing node with the same name the previously existing Node is returned, otherwise null is returned.

Throws:

DOMException - WRONG_DOCUMENT_ERR: Raised if arg was created from a different document than the one that created the NamedNodeMap.

NO_MODIFICATION_ALLOWED_ERR: Raised if this NamedNodeMap is Read-only.

INUSE_ATTRIBUTE_ERR: Raised if arg is an Attr that is already an attribute of another Element object. The DOM user must explicitly clone Attr nodes to reuse them in other elements.