Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file and, per its terms, should not be removed: * * Copyright (c) 2004 World Wide Web Consortium, * * (Massachusetts Institute of Technology, European Research Consortium for * Informatics and Mathematics, Keio University). All Rights Reserved. This * work is distributed under the W3C(r) Software License [1] 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. * * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231 */ package org.w3c.dom; /** * The <code>Attr</code> interface represents an attribute in an * <code>Element</code> object. Typically the allowable values for the * attribute are defined in a schema associated with the document. * <p><code>Attr</code> objects inherit the <code>Node</code> interface, but * since they are not actually child nodes of the element they describe, the * DOM does not consider them part of the document tree. Thus, the * <code>Node</code> attributes <code>parentNode</code>, * <code>previousSibling</code>, and <code>nextSibling</code> have a * <code>null</code> value for <code>Attr</code> objects. The DOM takes the * view that attributes are properties of elements rather than having a * separate identity from the elements they are associated with; this should * make it more efficient to implement such features as default attributes * associated with all elements of a given type. Furthermore, * <code>Attr</code> nodes may not be immediate children of a * <code>DocumentFragment</code>. However, they can be associated with * <code>Element</code> nodes contained within a * <code>DocumentFragment</code>. In short, users and implementors of the * DOM need to be aware that <code>Attr</code> nodes have some things in * common with other objects inheriting the <code>Node</code> interface, but * they also are quite distinct. * <p>The attribute's effective value is determined as follows: if this * attribute has been explicitly assigned any value, that value is the * attribute's effective value; otherwise, if there is a declaration for * this attribute, and that declaration includes a default value, then that * default value is the attribute's effective value; otherwise, the * attribute does not exist on this element in the structure model until it * has been explicitly added. Note that the <code>Node.nodeValue</code> * attribute on the <code>Attr</code> instance can also be used to retrieve * the string version of the attribute's value(s). * <p> If the attribute was not explicitly given a value in the instance * document but has a default value provided by the schema associated with * the document, an attribute node will be created with * <code>specified</code> set to <code>false</code>. Removing attribute * nodes for which a default value is defined in the schema generates a new * attribute node with the default value and <code>specified</code> set to * <code>false</code>. If validation occurred while invoking * <code>Document.normalizeDocument()</code>, attribute nodes with * <code>specified</code> equals to <code>false</code> are recomputed * according to the default attribute values provided by the schema. If no * default value is associate with this attribute in the schema, the * attribute node is discarded. * <p>In XML, where the value of an attribute can contain entity references, * the child nodes of the <code>Attr</code> node may be either * <code>Text</code> or <code>EntityReference</code> nodes (when these are * in use; see the description of <code>EntityReference</code> for * discussion). * <p>The DOM Core represents all attribute values as simple strings, even if * the DTD or schema associated with the document declares them of some * specific type such as tokenized. * <p>The way attribute value normalization is performed by the DOM * implementation depends on how much the implementation knows about the * schema in use. Typically, the <code>value</code> and * <code>nodeValue</code> attributes of an <code>Attr</code> node initially * returns the normalized value given by the parser. It is also the case * after <code>Document.normalizeDocument()</code> is called (assuming the * right options have been set). But this may not be the case after * mutation, independently of whether the mutation is performed by setting * the string value directly or by changing the <code>Attr</code> child * nodes. In particular, this is true when <a href='http://www.w3.org/TR/2004/REC-xml-20040204#dt-charref'>character * references</a> are involved, given that they are not represented in the DOM and they * impact attribute value normalization. On the other hand, if the * implementation knows about the schema in use when the attribute value is * changed, and it is of a different type than CDATA, it may normalize it * again at that time. This is especially true of specialized DOM * implementations, such as SVG DOM implementations, which store attribute * values in an internal form different from a string. * <p>The following table gives some examples of the relations between the * attribute value in the original document (parsed attribute), the value as * exposed in the DOM, and the serialization of the value: * <table class="striped"> * <caption>Examples of the Original, Normalized and Serialized Values </caption> * <thead> * <tr> * <th scope="col">Examples</th> * <th scope="col">Parsed * attribute value</th> * <th scope="col">Initial <code>Attr.value</code></th> * <th scope="col">Serialized attribute value</th> * </tr> * </thead> * <tbody> * <tr> * <th scope="row" valign='top' rowspan='1' colspan='1'> * Character reference</th> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x&#178;=5"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x²=5"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x&#178;=5"</pre> * </td> * </tr> * <tr> * <th scope="row" valign='top' rowspan='1' colspan='1'>Built-in * character entity</th> * <td valign='top' rowspan='1' colspan='1'> * <pre>"y&lt;6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"y<6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"y&lt;6"</pre> * </td> * </tr> * <tr> * <th scope="row" valign='top' rowspan='1' colspan='1'>Literal newline between</th> * <td valign='top' rowspan='1' colspan='1'> * <pre> * "x=5&#10;y=6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x=5 y=6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x=5&#10;y=6"</pre> * </td> * </tr> * <tr> * <th scope="row" valign='top' rowspan='1' colspan='1'>Normalized newline between</th> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x=5 * y=6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x=5 y=6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'> * <pre>"x=5 y=6"</pre> * </td> * </tr> * <tr> * <th scope="row" valign='top' rowspan='1' colspan='1'>Entity <code>e</code> with literal newline</th> * <td valign='top' rowspan='1' colspan='1'> * <pre> * <!ENTITY e '...&#10;...'> [...]> "x=5&e;y=6"</pre> * </td> * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load Options</em></td> * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load/Save Options</em></td> * </tr> * </tbody> * </table> * <p>See also the <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407'>Document Object Model (DOM) Level 3 Core Specification</a>. */ public interface Attr extends Node { /** * Returns the name of this attribute. If <code>Node.localName</code> is * different from <code>null</code>, this attribute is a qualified name. */ public String getName(); /** * <code>True</code> if this attribute was explicitly given a value in * the instance document, <code>false</code> otherwise. If the * application changed the value of this attribute node (even if it ends * up having the same value as the default value) then it is set to * <code>true</code>. The implementation may handle attributes with * default values from other schemas similarly but applications should * use <code>Document.normalizeDocument()</code> to guarantee this * information is up-to-date. */ public boolean getSpecified(); /** * On retrieval, the value of the attribute is returned as a string. * Character and general entity references are replaced with their * values. See also the method <code>getAttribute</code> on the * <code>Element</code> interface. * <br>On setting, this creates a <code>Text</code> node with the unparsed * contents of the string, i.e. any characters that an XML processor * would recognize as markup are instead treated as literal text. See * also the method <code>Element.setAttribute()</code>. * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>] * implementations, may do normalization automatically, even after * mutation; in such case, the value on retrieval may differ from the * value on setting. */ public String getValue(); /** * On retrieval, the value of the attribute is returned as a string. * Character and general entity references are replaced with their * values. See also the method <code>getAttribute</code> on the * <code>Element</code> interface. * <br>On setting, this creates a <code>Text</code> node with the unparsed * contents of the string, i.e. any characters that an XML processor * would recognize as markup are instead treated as literal text. See * also the method <code>Element.setAttribute()</code>. * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>] * implementations, may do normalization automatically, even after * mutation; in such case, the value on retrieval may differ from the * value on setting. * @exception DOMException * NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. */ public void setValue(String value) throws DOMException; /** * The <code>Element</code> node this attribute is attached to or * <code>null</code> if this attribute is not in use. * @since 1.4, DOM Level 2 */ public Element getOwnerElement(); /** * The type information associated with this attribute. While the type * information contained in this attribute is guarantee to be correct * after loading the document or invoking * <code>Document.normalizeDocument()</code>, <code>schemaTypeInfo</code> * may not be reliable if the node was moved. * @since 1.5, DOM Level 3 */ public TypeInfo getSchemaTypeInfo(); /** * Returns whether this attribute is known to be of type ID (i.e. to * contain an identifier for its owner element) or not. When it is and * its value is unique, the <code>ownerElement</code> of this attribute * can be retrieved using the method <code>Document.getElementById</code> * . The implementation could use several ways to determine if an * attribute node is known to contain an identifier: * <ul> * <li> If validation * occurred using an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>] * while loading the document or while invoking * <code>Document.normalizeDocument()</code>, the post-schema-validation * infoset contributions (PSVI contributions) values are used to * determine if this attribute is a schema-determined ID attribute using * the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-sdi'> * schema-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>] * . * </li> * <li> If validation occurred using a DTD while loading the document or * while invoking <code>Document.normalizeDocument()</code>, the infoset <b>[type definition]</b> value is used to determine if this attribute is a DTD-determined ID * attribute using the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-ddi'> * DTD-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>] * . * </li> * <li> from the use of the methods <code>Element.setIdAttribute()</code>, * <code>Element.setIdAttributeNS()</code>, or * <code>Element.setIdAttributeNode()</code>, i.e. it is an * user-determined ID attribute; * <p ><b>Note:</b> XPointer framework (see section 3.2 in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>] * ) consider the DOM user-determined ID attribute as being part of the * XPointer externally-determined ID definition. * </li> * <li> using mechanisms that * are outside the scope of this specification, it is then an * externally-determined ID attribute. This includes using schema * languages different from XML schema and DTD. * </li> * </ul> * <br> If validation occurred while invoking * <code>Document.normalizeDocument()</code>, all user-determined ID * attributes are reset and all attribute nodes ID information are then * reevaluated in accordance to the schema used. As a consequence, if * the <code>Attr.schemaTypeInfo</code> attribute contains an ID type, * <code>isId</code> will always return true. * @since 1.5, DOM Level 3 */ public boolean isId(); }