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1: /* 2: * Copyright (c) 2004 World Wide Web Consortium, 3: * 4: * (Massachusetts Institute of Technology, European Research Consortium for 5: * Informatics and Mathematics, Keio University). All Rights Reserved. This 6: * work is distributed under the W3C(r) Software License [1] in the hope that 7: * it will be useful, but WITHOUT ANY WARRANTY; without even the implied 8: * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 9: * 10: * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231 11: */ 12: 13: package org.w3c.dom; 14: 15: /** 16: * The <code>Attr</code> interface represents an attribute in an 17: * <code>Element</code> object. Typically the allowable values for the 18: * attribute are defined in a schema associated with the document. 19: * <p><code>Attr</code> objects inherit the <code>Node</code> interface, but 20: * since they are not actually child nodes of the element they describe, the 21: * DOM does not consider them part of the document tree. Thus, the 22: * <code>Node</code> attributes <code>parentNode</code>, 23: * <code>previousSibling</code>, and <code>nextSibling</code> have a 24: * <code>null</code> value for <code>Attr</code> objects. The DOM takes the 25: * view that attributes are properties of elements rather than having a 26: * separate identity from the elements they are associated with; this should 27: * make it more efficient to implement such features as default attributes 28: * associated with all elements of a given type. Furthermore, 29: * <code>Attr</code> nodes may not be immediate children of a 30: * <code>DocumentFragment</code>. However, they can be associated with 31: * <code>Element</code> nodes contained within a 32: * <code>DocumentFragment</code>. In short, users and implementors of the 33: * DOM need to be aware that <code>Attr</code> nodes have some things in 34: * common with other objects inheriting the <code>Node</code> interface, but 35: * they also are quite distinct. 36: * <p>The attribute's effective value is determined as follows: if this 37: * attribute has been explicitly assigned any value, that value is the 38: * attribute's effective value; otherwise, if there is a declaration for 39: * this attribute, and that declaration includes a default value, then that 40: * default value is the attribute's effective value; otherwise, the 41: * attribute does not exist on this element in the structure model until it 42: * has been explicitly added. Note that the <code>Node.nodeValue</code> 43: * attribute on the <code>Attr</code> instance can also be used to retrieve 44: * the string version of the attribute's value(s). 45: * <p> If the attribute was not explicitly given a value in the instance 46: * document but has a default value provided by the schema associated with 47: * the document, an attribute node will be created with 48: * <code>specified</code> set to <code>false</code>. Removing attribute 49: * nodes for which a default value is defined in the schema generates a new 50: * attribute node with the default value and <code>specified</code> set to 51: * <code>false</code>. If validation occurred while invoking 52: * <code>Document.normalizeDocument()</code>, attribute nodes with 53: * <code>specified</code> equals to <code>false</code> are recomputed 54: * according to the default attribute values provided by the schema. If no 55: * default value is associate with this attribute in the schema, the 56: * attribute node is discarded. 57: * <p>In XML, where the value of an attribute can contain entity references, 58: * the child nodes of the <code>Attr</code> node may be either 59: * <code>Text</code> or <code>EntityReference</code> nodes (when these are 60: * in use; see the description of <code>EntityReference</code> for 61: * discussion). 62: * <p>The DOM Core represents all attribute values as simple strings, even if 63: * the DTD or schema associated with the document declares them of some 64: * specific type such as tokenized. 65: * <p>The way attribute value normalization is performed by the DOM 66: * implementation depends on how much the implementation knows about the 67: * schema in use. Typically, the <code>value</code> and 68: * <code>nodeValue</code> attributes of an <code>Attr</code> node initially 69: * returns the normalized value given by the parser. It is also the case 70: * after <code>Document.normalizeDocument()</code> is called (assuming the 71: * right options have been set). But this may not be the case after 72: * mutation, independently of whether the mutation is performed by setting 73: * the string value directly or by changing the <code>Attr</code> child 74: * nodes. In particular, this is true when <a href='http://www.w3.org/TR/2004/REC-xml-20040204#dt-charref'>character 75: * references</a> are involved, given that they are not represented in the DOM and they 76: * impact attribute value normalization. On the other hand, if the 77: * implementation knows about the schema in use when the attribute value is 78: * changed, and it is of a different type than CDATA, it may normalize it 79: * again at that time. This is especially true of specialized DOM 80: * implementations, such as SVG DOM implementations, which store attribute 81: * values in an internal form different from a string. 82: * <p>The following table gives some examples of the relations between the 83: * attribute value in the original document (parsed attribute), the value as 84: * exposed in the DOM, and the serialization of the value: 85: * <table border='1' cellpadding='3'> 86: * <tr> 87: * <th>Examples</th> 88: * <th>Parsed 89: * attribute value</th> 90: * <th>Initial <code>Attr.value</code></th> 91: * <th>Serialized attribute value</th> 92: * </tr> 93: * <tr> 94: * <td valign='top' rowspan='1' colspan='1'> 95: * Character reference</td> 96: * <td valign='top' rowspan='1' colspan='1'> 97: * <pre>"x&#178;=5"</pre> 98: * </td> 99: * <td valign='top' rowspan='1' colspan='1'> 100: * <pre>"x\u00b2=5"</pre> 101: * </td> 102: * <td valign='top' rowspan='1' colspan='1'> 103: * <pre>"x&#178;=5"</pre> 104: * </td> 105: * </tr> 106: * <tr> 107: * <td valign='top' rowspan='1' colspan='1'>Built-in 108: * character entity</td> 109: * <td valign='top' rowspan='1' colspan='1'> 110: * <pre>"y&lt;6"</pre> 111: * </td> 112: * <td valign='top' rowspan='1' colspan='1'> 113: * <pre>"y<6"</pre> 114: * </td> 115: * <td valign='top' rowspan='1' colspan='1'> 116: * <pre>"y&lt;6"</pre> 117: * </td> 118: * </tr> 119: * <tr> 120: * <td valign='top' rowspan='1' colspan='1'>Literal newline between</td> 121: * <td valign='top' rowspan='1' colspan='1'> 122: * <pre> 123: * "x=5&#10;y=6"</pre> 124: * </td> 125: * <td valign='top' rowspan='1' colspan='1'> 126: * <pre>"x=5 y=6"</pre> 127: * </td> 128: * <td valign='top' rowspan='1' colspan='1'> 129: * <pre>"x=5&#10;y=6"</pre> 130: * </td> 131: * </tr> 132: * <tr> 133: * <td valign='top' rowspan='1' colspan='1'>Normalized newline between</td> 134: * <td valign='top' rowspan='1' colspan='1'> 135: * <pre>"x=5 136: * y=6"</pre> 137: * </td> 138: * <td valign='top' rowspan='1' colspan='1'> 139: * <pre>"x=5 y=6"</pre> 140: * </td> 141: * <td valign='top' rowspan='1' colspan='1'> 142: * <pre>"x=5 y=6"</pre> 143: * </td> 144: * </tr> 145: * <tr> 146: * <td valign='top' rowspan='1' colspan='1'>Entity <code>e</code> with literal newline</td> 147: * <td valign='top' rowspan='1' colspan='1'> 148: * <pre> 149: * <!ENTITY e '...&#10;...'> [...]> "x=5&e;y=6"</pre> 150: * </td> 151: * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load Options</em></td> 152: * <td valign='top' rowspan='1' colspan='1'><em>Dependent on Implementation and Load/Save Options</em></td> 153: * </tr> 154: * </table> 155: * <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>. 156: */ 157: public interface Attr extends Node { 158: /** 159: * Returns the name of this attribute. If <code>Node.localName</code> is 160: * different from <code>null</code>, this attribute is a qualified name. 161: */ 162: public String getName(); 163: 164: /** 165: * <code>True</code> if this attribute was explicitly given a value in 166: * the instance document, <code>false</code> otherwise. If the 167: * application changed the value of this attribute node (even if it ends 168: * up having the same value as the default value) then it is set to 169: * <code>true</code>. The implementation may handle attributes with 170: * default values from other schemas similarly but applications should 171: * use <code>Document.normalizeDocument()</code> to guarantee this 172: * information is up-to-date. 173: */ 174: public boolean getSpecified(); 175: 176: /** 177: * On retrieval, the value of the attribute is returned as a string. 178: * Character and general entity references are replaced with their 179: * values. See also the method <code>getAttribute</code> on the 180: * <code>Element</code> interface. 181: * <br>On setting, this creates a <code>Text</code> node with the unparsed 182: * contents of the string, i.e. any characters that an XML processor 183: * would recognize as markup are instead treated as literal text. See 184: * also the method <code>Element.setAttribute()</code>. 185: * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>] 186: * implementations, may do normalization automatically, even after 187: * mutation; in such case, the value on retrieval may differ from the 188: * value on setting. 189: */ 190: public String getValue(); 191: /** 192: * On retrieval, the value of the attribute is returned as a string. 193: * Character and general entity references are replaced with their 194: * values. See also the method <code>getAttribute</code> on the 195: * <code>Element</code> interface. 196: * <br>On setting, this creates a <code>Text</code> node with the unparsed 197: * contents of the string, i.e. any characters that an XML processor 198: * would recognize as markup are instead treated as literal text. See 199: * also the method <code>Element.setAttribute()</code>. 200: * <br> Some specialized implementations, such as some [<a href='http://www.w3.org/TR/2003/REC-SVG11-20030114/'>SVG 1.1</a>] 201: * implementations, may do normalization automatically, even after 202: * mutation; in such case, the value on retrieval may differ from the 203: * value on setting. 204: * @exception DOMException 205: * NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. 206: */ 207: public void setValue(String value) 208: throws DOMException; 209: 210: /** 211: * The <code>Element</code> node this attribute is attached to or 212: * <code>null</code> if this attribute is not in use. 213: * @since DOM Level 2 214: */ 215: public Element getOwnerElement(); 216: 217: /** 218: * The type information associated with this attribute. While the type 219: * information contained in this attribute is guarantee to be correct 220: * after loading the document or invoking 221: * <code>Document.normalizeDocument()</code>, <code>schemaTypeInfo</code> 222: * may not be reliable if the node was moved. 223: * @since DOM Level 3 224: */ 225: public TypeInfo getSchemaTypeInfo(); 226: 227: /** 228: * Returns whether this attribute is known to be of type ID (i.e. to 229: * contain an identifier for its owner element) or not. When it is and 230: * its value is unique, the <code>ownerElement</code> of this attribute 231: * can be retrieved using the method <code>Document.getElementById</code> 232: * . The implementation could use several ways to determine if an 233: * attribute node is known to contain an identifier: 234: * <ul> 235: * <li> If validation 236: * occurred using an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>] 237: * while loading the document or while invoking 238: * <code>Document.normalizeDocument()</code>, the post-schema-validation 239: * infoset contributions (PSVI contributions) values are used to 240: * determine if this attribute is a schema-determined ID attribute using 241: * the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-sdi'> 242: * schema-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>] 243: * . 244: * </li> 245: * <li> If validation occurred using a DTD while loading the document or 246: * 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 247: * attribute using the <a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/#term-ddi'> 248: * DTD-determined ID</a> definition in [<a href='http://www.w3.org/TR/2003/REC-xptr-framework-20030325/'>XPointer</a>] 249: * . 250: * </li> 251: * <li> from the use of the methods <code>Element.setIdAttribute()</code>, 252: * <code>Element.setIdAttributeNS()</code>, or 253: * <code>Element.setIdAttributeNode()</code>, i.e. it is an 254: * user-determined ID attribute; 255: * <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>] 256: * ) consider the DOM user-determined ID attribute as being part of the 257: * XPointer externally-determined ID definition. 258: * </li> 259: * <li> using mechanisms that 260: * are outside the scope of this specification, it is then an 261: * externally-determined ID attribute. This includes using schema 262: * languages different from XML schema and DTD. 263: * </li> 264: * </ul> 265: * <br> If validation occurred while invoking 266: * <code>Document.normalizeDocument()</code>, all user-determined ID 267: * attributes are reset and all attribute nodes ID information are then 268: * reevaluated in accordance to the schema used. As a consequence, if 269: * the <code>Attr.schemaTypeInfo</code> attribute contains an ID type, 270: * <code>isId</code> will always return true. 271: * @since DOM Level 3 272: */ 273: public boolean isId(); 274: 275: }