jaxp/src/org/w3c/dom/Attr.java
changeset 12457 c348e06f0e82
parent 12005 a754d69d5e60
child 25262 1fe892ba017a
equal deleted inserted replaced
12324:1d7e6da6adc8 12457:c348e06f0e82
       
     1 /*
       
     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     3  *
       
     4  * This code is free software; you can redistribute it and/or modify it
       
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     7  * particular file as subject to the "Classpath" exception as provided
       
     8  * by Oracle in the LICENSE file that accompanied this code.
       
     9  *
       
    10  * This code is distributed in the hope that it will be useful, but WITHOUT
       
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    12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    13  * version 2 for more details (a copy is included in the LICENSE file that
       
    14  * accompanied this code).
       
    15  *
       
    16  * You should have received a copy of the GNU General Public License version
       
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    24 
       
    25 /*
       
    26  * This file is available under and governed by the GNU General Public
       
    27  * License version 2 only, as published by the Free Software Foundation.
       
    28  * However, the following notice accompanied the original version of this
       
    29  * file and, per its terms, should not be removed:
       
    30  *
       
    31  * Copyright (c) 2004 World Wide Web Consortium,
       
    32  *
       
    33  * (Massachusetts Institute of Technology, European Research Consortium for
       
    34  * Informatics and Mathematics, Keio University). All Rights Reserved. This
       
    35  * work is distributed under the W3C(r) Software License [1] in the hope that
       
    36  * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
       
    37  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       
    38  *
       
    39  * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
       
    40  */
       
    41 
       
    42 package org.w3c.dom;
       
    43 
       
    44 /**
       
    45  * The <code>Attr</code> interface represents an attribute in an
       
    46  * <code>Element</code> object. Typically the allowable values for the
       
    47  * attribute are defined in a schema associated with the document.
       
    48  * <p><code>Attr</code> objects inherit the <code>Node</code> interface, but
       
    49  * since they are not actually child nodes of the element they describe, the
       
    50  * DOM does not consider them part of the document tree. Thus, the
       
    51  * <code>Node</code> attributes <code>parentNode</code>,
       
    52  * <code>previousSibling</code>, and <code>nextSibling</code> have a
       
    53  * <code>null</code> value for <code>Attr</code> objects. The DOM takes the
       
    54  * view that attributes are properties of elements rather than having a
       
    55  * separate identity from the elements they are associated with; this should
       
    56  * make it more efficient to implement such features as default attributes
       
    57  * associated with all elements of a given type. Furthermore,
       
    58  * <code>Attr</code> nodes may not be immediate children of a
       
    59  * <code>DocumentFragment</code>. However, they can be associated with
       
    60  * <code>Element</code> nodes contained within a
       
    61  * <code>DocumentFragment</code>. In short, users and implementors of the
       
    62  * DOM need to be aware that <code>Attr</code> nodes have some things in
       
    63  * common with other objects inheriting the <code>Node</code> interface, but
       
    64  * they also are quite distinct.
       
    65  * <p>The attribute's effective value is determined as follows: if this
       
    66  * attribute has been explicitly assigned any value, that value is the
       
    67  * attribute's effective value; otherwise, if there is a declaration for
       
    68  * this attribute, and that declaration includes a default value, then that
       
    69  * default value is the attribute's effective value; otherwise, the
       
    70  * attribute does not exist on this element in the structure model until it
       
    71  * has been explicitly added. Note that the <code>Node.nodeValue</code>
       
    72  * attribute on the <code>Attr</code> instance can also be used to retrieve
       
    73  * the string version of the attribute's value(s).
       
    74  * <p> If the attribute was not explicitly given a value in the instance
       
    75  * document but has a default value provided by the schema associated with
       
    76  * the document, an attribute node will be created with
       
    77  * <code>specified</code> set to <code>false</code>. Removing attribute
       
    78  * nodes for which a default value is defined in the schema generates a new
       
    79  * attribute node with the default value and <code>specified</code> set to
       
    80  * <code>false</code>. If validation occurred while invoking
       
    81  * <code>Document.normalizeDocument()</code>, attribute nodes with
       
    82  * <code>specified</code> equals to <code>false</code> are recomputed
       
    83  * according to the default attribute values provided by the schema. If no
       
    84  * default value is associate with this attribute in the schema, the
       
    85  * attribute node is discarded.
       
    86  * <p>In XML, where the value of an attribute can contain entity references,
       
    87  * the child nodes of the <code>Attr</code> node may be either
       
    88  * <code>Text</code> or <code>EntityReference</code> nodes (when these are
       
    89  * in use; see the description of <code>EntityReference</code> for
       
    90  * discussion).
       
    91  * <p>The DOM Core represents all attribute values as simple strings, even if
       
    92  * the DTD or schema associated with the document declares them of some
       
    93  * specific type such as tokenized.
       
    94  * <p>The way attribute value normalization is performed by the DOM
       
    95  * implementation depends on how much the implementation knows about the
       
    96  * schema in use. Typically, the <code>value</code> and
       
    97  * <code>nodeValue</code> attributes of an <code>Attr</code> node initially
       
    98  * returns the normalized value given by the parser. It is also the case
       
    99  * after <code>Document.normalizeDocument()</code> is called (assuming the
       
   100  * right options have been set). But this may not be the case after
       
   101  * mutation, independently of whether the mutation is performed by setting
       
   102  * the string value directly or by changing the <code>Attr</code> child
       
   103  * nodes. In particular, this is true when <a href='http://www.w3.org/TR/2004/REC-xml-20040204#dt-charref'>character
       
   104  * references</a> are involved, given that they are not represented in the DOM and they
       
   105  * impact attribute value normalization. On the other hand, if the
       
   106  * implementation knows about the schema in use when the attribute value is
       
   107  * changed, and it is of a different type than CDATA, it may normalize it
       
   108  * again at that time. This is especially true of specialized DOM
       
   109  * implementations, such as SVG DOM implementations, which store attribute
       
   110  * values in an internal form different from a string.
       
   111  * <p>The following table gives some examples of the relations between the
       
   112  * attribute value in the original document (parsed attribute), the value as
       
   113  * exposed in the DOM, and the serialization of the value:
       
   114  * <table border='1' cellpadding='3'>
       
   115  * <tr>
       
   116  * <th>Examples</th>
       
   117  * <th>Parsed
       
   118  * attribute value</th>
       
   119  * <th>Initial <code>Attr.value</code></th>
       
   120  * <th>Serialized attribute value</th>
       
   121  * </tr>
       
   122  * <tr>
       
   123  * <td valign='top' rowspan='1' colspan='1'>
       
   124  * Character reference</td>
       
   125  * <td valign='top' rowspan='1' colspan='1'>
       
   126  * <pre>"x&amp;#178;=5"</pre>
       
   127  * </td>
       
   128  * <td valign='top' rowspan='1' colspan='1'>
       
   129  * <pre>"x\u00b2=5"</pre>
       
   130  * </td>
       
   131  * <td valign='top' rowspan='1' colspan='1'>
       
   132  * <pre>"x&amp;#178;=5"</pre>
       
   133  * </td>
       
   134  * </tr>
       
   135  * <tr>
       
   136  * <td valign='top' rowspan='1' colspan='1'>Built-in
       
   137  * character entity</td>
       
   138  * <td valign='top' rowspan='1' colspan='1'>
       
   139  * <pre>"y&amp;lt;6"</pre>
       
   140  * </td>
       
   141  * <td valign='top' rowspan='1' colspan='1'>
       
   142  * <pre>"y&lt;6"</pre>
       
   143  * </td>
       
   144  * <td valign='top' rowspan='1' colspan='1'>
       
   145  * <pre>"y&amp;lt;6"</pre>
       
   146  * </td>
       
   147  * </tr>
       
   148  * <tr>
       
   149  * <td valign='top' rowspan='1' colspan='1'>Literal newline between</td>
       
   150  * <td valign='top' rowspan='1' colspan='1'>
       
   151  * <pre>
       
   152  * "x=5&amp;#10;y=6"</pre>
       
   153  * </td>
       
   154  * <td valign='top' rowspan='1' colspan='1'>
       
   155  * <pre>"x=5 y=6"</pre>
       
   156  * </td>
       
   157  * <td valign='top' rowspan='1' colspan='1'>
       
   158  * <pre>"x=5&amp;#10;y=6"</pre>
       
   159  * </td>
       
   160  * </tr>
       
   161  * <tr>
       
   162  * <td valign='top' rowspan='1' colspan='1'>Normalized newline between</td>
       
   163  * <td valign='top' rowspan='1' colspan='1'>
       
   164  * <pre>"x=5
       
   165  * y=6"</pre>
       
   166  * </td>
       
   167  * <td valign='top' rowspan='1' colspan='1'>
       
   168  * <pre>"x=5 y=6"</pre>
       
   169  * </td>
       
   170  * <td valign='top' rowspan='1' colspan='1'>
       
   171  * <pre>"x=5 y=6"</pre>
       
   172  * </td>
       
   173  * </tr>
       
   174  * <tr>
       
   175  * <td valign='top' rowspan='1' colspan='1'>Entity <code>e</code> with literal newline</td>
       
   176  * <td valign='top' rowspan='1' colspan='1'>
       
   177  * <pre>
       
   178  * &lt;!ENTITY e '...&amp;#10;...'&gt; [...]&gt; "x=5&amp;e;y=6"</pre>
       
   179  * </td>
       
   180  * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load Options</em></td>
       
   181  * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load/Save Options</em></td>
       
   182  * </tr>
       
   183  * </table>
       
   184  * <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>.
       
   185  */
       
   186 public interface Attr extends Node {
       
   187     /**
       
   188      * Returns the name of this attribute. If <code>Node.localName</code> is
       
   189      * different from <code>null</code>, this attribute is a qualified name.
       
   190      */
       
   191     public String getName();
       
   192 
       
   193     /**
       
   194      *  <code>True</code> if this attribute was explicitly given a value in
       
   195      * the instance document, <code>false</code> otherwise. If the
       
   196      * application changed the value of this attribute node (even if it ends
       
   197      * up having the same value as the default value) then it is set to
       
   198      * <code>true</code>. The implementation may handle attributes with
       
   199      * default values from other schemas similarly but applications should
       
   200      * use <code>Document.normalizeDocument()</code> to guarantee this
       
   201      * information is up-to-date.
       
   202      */
       
   203     public boolean getSpecified();
       
   204 
       
   205     /**
       
   206      * On retrieval, the value of the attribute is returned as a string.
       
   207      * Character and general entity references are replaced with their
       
   208      * values. See also the method <code>getAttribute</code> on the
       
   209      * <code>Element</code> interface.
       
   210      * <br>On setting, this creates a <code>Text</code> node with the unparsed
       
   211      * contents of the string, i.e. any characters that an XML processor
       
   212      * would recognize as markup are instead treated as literal text. See
       
   213      * also the method <code>Element.setAttribute()</code>.
       
   214      * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>]
       
   215      * implementations, may do normalization automatically, even after
       
   216      * mutation; in such case, the value on retrieval may differ from the
       
   217      * value on setting.
       
   218      */
       
   219     public String getValue();
       
   220     /**
       
   221      * On retrieval, the value of the attribute is returned as a string.
       
   222      * Character and general entity references are replaced with their
       
   223      * values. See also the method <code>getAttribute</code> on the
       
   224      * <code>Element</code> interface.
       
   225      * <br>On setting, this creates a <code>Text</code> node with the unparsed
       
   226      * contents of the string, i.e. any characters that an XML processor
       
   227      * would recognize as markup are instead treated as literal text. See
       
   228      * also the method <code>Element.setAttribute()</code>.
       
   229      * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>]
       
   230      * implementations, may do normalization automatically, even after
       
   231      * mutation; in such case, the value on retrieval may differ from the
       
   232      * value on setting.
       
   233      * @exception DOMException
       
   234      *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
       
   235      */
       
   236     public void setValue(String value)
       
   237                             throws DOMException;
       
   238 
       
   239     /**
       
   240      * The <code>Element</code> node this attribute is attached to or
       
   241      * <code>null</code> if this attribute is not in use.
       
   242      * @since DOM Level 2
       
   243      */
       
   244     public Element getOwnerElement();
       
   245 
       
   246     /**
       
   247      *  The type information associated with this attribute. While the type
       
   248      * information contained in this attribute is guarantee to be correct
       
   249      * after loading the document or invoking
       
   250      * <code>Document.normalizeDocument()</code>, <code>schemaTypeInfo</code>
       
   251      *  may not be reliable if the node was moved.
       
   252      * @since DOM Level 3
       
   253      */
       
   254     public TypeInfo getSchemaTypeInfo();
       
   255 
       
   256     /**
       
   257      *  Returns whether this attribute is known to be of type ID (i.e. to
       
   258      * contain an identifier for its owner element) or not. When it is and
       
   259      * its value is unique, the <code>ownerElement</code> of this attribute
       
   260      * can be retrieved using the method <code>Document.getElementById</code>
       
   261      * . The implementation could use several ways to determine if an
       
   262      * attribute node is known to contain an identifier:
       
   263      * <ul>
       
   264      * <li> If validation
       
   265      * occurred using an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
       
   266      *  while loading the document or while invoking
       
   267      * <code>Document.normalizeDocument()</code>, the post-schema-validation
       
   268      * infoset contributions (PSVI contributions) values are used to
       
   269      * determine if this attribute is a schema-determined ID attribute using
       
   270      * the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-sdi'>
       
   271      * schema-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>]
       
   272      * .
       
   273      * </li>
       
   274      * <li> If validation occurred using a DTD while loading the document or
       
   275      * 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
       
   276      * attribute using the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-ddi'>
       
   277      * DTD-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>]
       
   278      * .
       
   279      * </li>
       
   280      * <li> from the use of the methods <code>Element.setIdAttribute()</code>,
       
   281      * <code>Element.setIdAttributeNS()</code>, or
       
   282      * <code>Element.setIdAttributeNode()</code>, i.e. it is an
       
   283      * user-determined ID attribute;
       
   284      * <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>]
       
   285      * ) consider the DOM user-determined ID attribute as being part of the
       
   286      * XPointer externally-determined ID definition.
       
   287      * </li>
       
   288      * <li> using mechanisms that
       
   289      * are outside the scope of this specification, it is then an
       
   290      * externally-determined ID attribute. This includes using schema
       
   291      * languages different from XML schema and DTD.
       
   292      * </li>
       
   293      * </ul>
       
   294      * <br> If validation occurred while invoking
       
   295      * <code>Document.normalizeDocument()</code>, all user-determined ID
       
   296      * attributes are reset and all attribute nodes ID information are then
       
   297      * reevaluated in accordance to the schema used. As a consequence, if
       
   298      * the <code>Attr.schemaTypeInfo</code> attribute contains an ID type,
       
   299      * <code>isId</code> will always return true.
       
   300      * @since DOM Level 3
       
   301      */
       
   302     public boolean isId();
       
   303 
       
   304 }