/*
 * Copyright (c) 2000 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See W3C License http://www.w3.org/Consortium/Legal/ for more
 * details.
 */

package org.w3c.dom;

/**
 *  Objects implementing the <code>NamedNodeMap</code> interface are used to 
 * represent collections of nodes that can be accessed by name. Note that 
 * <code>NamedNodeMap</code> does not inherit from <code>NodeList</code> ; 
 * <code>NamedNodeMaps</code> are not maintained in any particular order. 
 * Objects contained in an object implementing <code>NamedNodeMap</code> may 
 * also be accessed by an ordinal index, but this is simply to allow 
 * convenient enumeration of the contents of a <code>NamedNodeMap</code> , 
 * and does not imply that the DOM specifies an order to these Nodes. 
 */
public interface NamedNodeMap {
    /**
     *  Retrieves a node specified by name.
     * @param name  The <code>nodeName</code> of a node to retrieve.
     * @return  A <code>Node</code> (of any type) with the specified 
     *   <code>nodeName</code> , or <code>null</code> if it does not identify 
     *   any node in this map.
     */
    public Node getNamedItem(String name);

    /**
     *  Adds a node using its <code>nodeName</code> attribute. If a node with 
     * that name is already present in this map, it is replaced by the new 
     * one.
     * <br> As the <code>nodeName</code> 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.
     * @param arg  A node to store in this map. The node will later be 
     *   accessible using the value of its <code>nodeName</code> attribute.
     * @return  If the new <code>Node</code> replaces an existing node the 
     *   replaced <code>Node</code> is returned, otherwise <code>null</code> 
     *   is returned.
     * @exception DOMException
     *    WRONG_DOCUMENT_ERR: Raised if <code>arg</code> was created from a 
     *   different document than the one that created this map.
     *   <br> NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     *   <br> INUSE_ATTRIBUTE_ERR: Raised if <code>arg</code> is an 
     *   <code>Attr</code> that is already an attribute of another 
     *   <code>Element</code> object. The DOM user must explicitly clone 
     *   <code>Attr</code> nodes to re-use them in other elements.
     */
    public Node setNamedItem(Node arg)
                             throws DOMException;

    /**
     *  Removes a node specified by name. A removed attribute may be known to 
     * have a default value when this map contains the attributes attached to 
     * an element, as returned by the attributes attribute of the 
     * <code>Node</code> interface. If so, an attribute immediately appears 
     * containing the default value as well as the corresponding namespace 
     * URI, local name, and prefix when applicable.
     * @param name  The <code>nodeName</code> of the node to remove.
     * @return  The node removed from this map if a node with such a name 
     *   exists.
     * @exception DOMException
     *    NOT_FOUND_ERR: Raised if there is no node named <code>name</code> 
     *   in this map.
     *   <br> NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     */
    public Node removeNamedItem(String name)
                                throws DOMException;

    /**
     *  Returns the <code>index</code> th item in the map. If 
     * <code>index</code> is greater than or equal to the number of nodes in 
     * this map, this returns <code>null</code> .
     * @param index  Index into this map.
     * @return  The node at the <code>index</code> th position in the map, or 
     *   <code>null</code> if that is not a valid index.
     */
    public Node item(int index);

    /**
     *  The number of nodes in this map. The range of valid child node indices 
     * is <code>0</code> to <code>length-1</code> inclusive. 
     */
    public int getLength();

    /**
     *  Retrieves a node specified by local name and namespace URI. HTML-only 
     * DOM implementations do not need to implement this method.
     * @param namespaceURI  The  namespace URI of the node to retrieve.
     * @param localName  The  local name of the node to retrieve.
     * @return  A <code>Node</code> (of any type) with the specified local 
     *   name and namespace URI, or <code>null</code> if they do not identify 
     *   any node in this map.
     * @since DOM Level 2
     */
    public Node getNamedItemNS(String namespaceURI, 
                               String localName);

    /**
     *  Adds a node using its <code>namespaceURI</code> and 
     * <code>localName</code> . If a node with that namespace URI and that 
     * local name is already present in this map, it is replaced by the new 
     * one.
     * <br> HTML-only DOM implementations do not need to implement this method.
     * @param arg  A node to store in this map. The node will later be 
     *   accessible using the value of its <code>namespaceURI</code> and 
     *   <code>localName</code> attributes.
     * @return  If the new <code>Node</code> replaces an existing node the 
     *   replaced <code>Node</code> is returned, otherwise <code>null</code> 
     *   is returned.
     * @exception DOMException
     *    WRONG_DOCUMENT_ERR: Raised if <code>arg</code> was created from a 
     *   different document than the one that created this map.
     *   <br> NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     *   <br> INUSE_ATTRIBUTE_ERR: Raised if <code>arg</code> is an 
     *   <code>Attr</code> that is already an attribute of another 
     *   <code>Element</code> object. The DOM user must explicitly clone 
     *   <code>Attr</code> nodes to re-use them in other elements.
     * @since DOM Level 2
     */
    public Node setNamedItemNS(Node arg)
                               throws DOMException;

    /**
     *  Removes a node specified by local name and namespace URI. A removed 
     * attribute may be known to have a default value when this map contains 
     * the attributes attached to an element, as returned by the attributes 
     * attribute of the <code>Node</code> interface. If so, an attribute 
     * immediately appears containing the default value as well as the 
     * corresponding namespace URI, local name, and prefix when applicable.
     * <br> HTML-only DOM implementations do not need to implement this method.
     * @param namespaceURI  The  namespace URI of the node to remove.
     * @param localName  The  local name of the node to remove.
     * @return  The node removed from this map if a node with such a local 
     *   name and namespace URI exists.
     * @exception DOMException
     *    NOT_FOUND_ERR: Raised if there is no node with the specified 
     *   <code>namespaceURI</code> and <code>localName</code> in this map.
     *   <br> NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     * @since DOM Level 2
     */
    public Node removeNamedItemNS(String namespaceURI, 
                                  String localName)
                                  throws DOMException;

}