# Poco::XML

# class NamedNodeMap

Library: XML
Package: DOM
Header: Poco/DOM/NamedNodeMap.h

## Description

Objects implementing the NamedNodeMap interface are used to represent collections of nodes that can be accessed by name. Note that 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.

NamedNodeMap objects in the DOM are live.

A NamedNodeMap returned from a method must be released with a call to release() when no longer needed.

## Inheritance

Direct Base Classes: DOMObject

All Base Classes: DOMObject

Known Derived Classes: AttrMap, DTDMap

## Member Summary

Member Functions: getNamedItem, getNamedItemNS, item, length, removeNamedItem, removeNamedItemNS, setNamedItem, setNamedItemNS

Inherited Functions: autoRelease, duplicate, release

## Destructor

### ~NamedNodeMap

virtual ~NamedNodeMap();

## Member Functions

### getNamedItem

virtual Node * getNamedItem(
const XMLString & name
) const = 0;

Retrieves a node specified by name.

### getNamedItemNS

virtual Node * getNamedItemNS(
const XMLString & namespaceURI,
const XMLString & localName
) const = 0;

Retrieves a node specified by name.

### item

virtual Node * item(
unsigned long index
) const = 0;

Returns the index'th item in the map. If index is greater than or equal to the number of nodes in the map, this returns null.

### length

virtual unsigned long length() const = 0;

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

### removeNamedItem

virtual Node * removeNamedItem(
const XMLString & name
) = 0;

Removes a node specified by name. When this map contains the attributes attached to an element, if the removed attribute is known to have a default value, an attribute immediately appears containing the default value.

### removeNamedItemNS

virtual Node * removeNamedItemNS(
const XMLString & namespaceURI,
const XMLString & localName
) = 0;

Removes a node specified by name.

### setNamedItem

virtual Node * setNamedItem(
Node * arg
) = 0;

Adds a node using its nodeName attribute. If a node with that name is already present in this map, it is replaced by the new one. 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 aliased.

### setNamedItemNS

virtual Node * setNamedItemNS(
Node * arg
) = 0;

Adds a node using its nodeName attribute. If a node with that namespace URI and that local name is already present in this map, it is replaced by the new one.