001    /*
002     * Copyright (c) 2003 World Wide Web Consortium,
003     * (Massachusetts Institute of Technology, Institut National de
004     * Recherche en Informatique et en Automatique, Keio University). All
005     * Rights Reserved. This program is distributed under the W3C's Software
006     * Intellectual Property License. This program is distributed in the
007     * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
008     * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
009     * PURPOSE.
010     * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
011     */
012    
013    package org.w3c.dom.html2;
014    
015    import org.w3c.dom.Node;
016    
017    /**
018     * An <code>HTMLCollection</code> is a list of nodes. An individual node may 
019     * be accessed by either ordinal index or the node's <code>name</code> or 
020     * <code>id</code> attributes. Collections in the HTML DOM are assumed to be 
021     * live meaning that they are automatically updated when the underlying 
022     * document is changed. 
023     * <p>See also the <a href='http://www.w3.org/TR/2003/REC-DOM-Level-2-HTML-20030109'>Document Object Model (DOM) Level 2 HTML Specification</a>.
024     */
025    public interface HTMLCollection {
026        /**
027         * This attribute specifies the length or size of the list. 
028         */
029        public int getLength();
030    
031        /**
032         * This method retrieves a node specified by ordinal index. Nodes are 
033         * numbered in tree order (depth-first traversal order).
034         * @param index The index of the node to be fetched. The index origin is 
035         *   <code>0</code>.
036         * @return The <code>Node</code> at the corresponding position upon 
037         *   success. A value of <code>null</code> is returned if the index is 
038         *   out of range. 
039         */
040        public Node item(int index);
041    
042        /**
043         * This method retrieves a <code>Node</code> using a name. With [<a href='http://www.w3.org/TR/1999/REC-html401-19991224'>HTML 4.01</a>] 
044         * documents, it first searches for a <code>Node</code> with a matching 
045         * <code>id</code> attribute. If it doesn't find one, it then searches 
046         * for a <code>Node</code> with a matching <code>name</code> attribute, 
047         * but only on those elements that are allowed a name attribute. With [<a href='http://www.w3.org/TR/2002/REC-xhtml1-20020801'>XHTML 1.0</a>] 
048         * documents, this method only searches for <code>Nodes</code> with a 
049         * matching <code>id</code> attribute. This method is case insensitive 
050         * in HTML documents and case sensitive in XHTML documents.
051         * @param name The name of the <code>Node</code> to be fetched.
052         * @return The <code>Node</code> with a <code>name</code> or 
053         *   <code>id</code> attribute whose value corresponds to the specified 
054         *   string. Upon failure (e.g., no node with this name exists), returns 
055         *   <code>null</code>.
056         */
057        public Node namedItem(String name);
058    
059    }