1 // Attributes.java - attribute list with Namespace support 2 // http://www.saxproject.org 3 // Written by David Megginson 4 // NO WARRANTY! This class is in the public domain. 5 // $Id: Attributes.java,v 1.13 2004/03/18 12:28:05 dmegginson Exp $ 6 7 package org.xml.sax; 8 9 10 /** 11 * Interface for a list of XML attributes. 12 * 13 * <blockquote> 14 * <em>This module, both source code and documentation, is in the 15 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> 16 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a> 17 * for further information. 18 * </blockquote> 19 * 20 * <p>This interface allows access to a list of attributes in 21 * three different ways:</p> 22 * 23 * <ol> 24 * <li>by attribute index;</li> 25 * <li>by Namespace-qualified name; or</li> 26 * <li>by qualified (prefixed) name.</li> 27 * </ol> 28 * 29 * <p>The list will not contain attributes that were declared 30 * #IMPLIED but not specified in the start tag. It will also not 31 * contain attributes used as Namespace declarations (xmlns*) unless 32 * the <code>http://xml.org/sax/features/namespace-prefixes</code> 33 * feature is set to <var>true</var> (it is <var>false</var> by 34 * default). 35 * Because SAX2 conforms to the original "Namespaces in XML" 36 * recommendation, it normally does not 37 * give namespace declaration attributes a namespace URI. 38 * </p> 39 * 40 * <p>Some SAX2 parsers may support using an optional feature flag 41 * (<code>http://xml.org/sax/features/xmlns-uris</code>) to request 42 * that those attributes be given URIs, conforming to a later 43 * backwards-incompatible revision of that recommendation. (The 44 * attribute's "local name" will be the prefix, or "xmlns" when 45 * defining a default element namespace.) For portability, handler 46 * code should always resolve that conflict, rather than requiring 47 * parsers that can change the setting of that feature flag. </p> 48 * 49 * <p>If the namespace-prefixes feature (see above) is 50 * <var>false</var>, access by qualified name may not be available; if 51 * the <code>http://xml.org/sax/features/namespaces</code> feature is 52 * <var>false</var>, access by Namespace-qualified names may not be 53 * available.</p> 54 * 55 * <p>This interface replaces the now-deprecated SAX1 {@link 56 * org.xml.sax.AttributeList AttributeList} interface, which does not 57 * contain Namespace support. In addition to Namespace support, it 58 * adds the <var>getIndex</var> methods (below).</p> 59 * 60 * <p>The order of attributes in the list is unspecified, and will 61 * vary from implementation to implementation.</p> 62 * 63 * @since SAX 2.0 64 * @author David Megginson 65 * @version 2.0.1 (sax2r2) 66 * @see org.xml.sax.helpers.AttributesImpl 67 * @see org.xml.sax.ext.DeclHandler#attributeDecl 68 */ 69 public interface Attributes 70 { 71 72 73 //////////////////////////////////////////////////////////////////// 74 // Indexed access. 75 //////////////////////////////////////////////////////////////////// 76 77 78 /** 79 * Return the number of attributes in the list. 80 * 81 * <p>Once you know the number of attributes, you can iterate 82 * through the list.</p> 83 * 84 * @return The number of attributes in the list. 85 * @see #getURI(int) 86 * @see #getLocalName(int) 87 * @see #getQName(int) 88 * @see #getType(int) 89 * @see #getValue(int) 90 */ getLength()91 public abstract int getLength (); 92 93 94 /** 95 * Look up an attribute's Namespace URI by index. 96 * 97 * @param index The attribute index (zero-based). 98 * @return The Namespace URI, or the empty string if none 99 * is available, or null if the index is out of 100 * range. 101 * @see #getLength 102 */ getURI(int index)103 public abstract String getURI (int index); 104 105 106 /** 107 * Look up an attribute's local name by index. 108 * 109 * @param index The attribute index (zero-based). 110 * @return The local name, or the empty string if Namespace 111 * processing is not being performed, or null 112 * if the index is out of range. 113 * @see #getLength 114 */ getLocalName(int index)115 public abstract String getLocalName (int index); 116 117 118 /** 119 * Look up an attribute's XML qualified (prefixed) name by index. 120 * 121 * @param index The attribute index (zero-based). 122 * @return The XML qualified name, or the empty string 123 * if none is available, or null if the index 124 * is out of range. 125 * @see #getLength 126 */ getQName(int index)127 public abstract String getQName (int index); 128 129 130 /** 131 * Look up an attribute's type by index. 132 * 133 * <p>The attribute type is one of the strings "CDATA", "ID", 134 * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES", 135 * or "NOTATION" (always in upper case).</p> 136 * 137 * <p>If the parser has not read a declaration for the attribute, 138 * or if the parser does not report attribute types, then it must 139 * return the value "CDATA" as stated in the XML 1.0 Recommendation 140 * (clause 3.3.3, "Attribute-Value Normalization").</p> 141 * 142 * <p>For an enumerated attribute that is not a notation, the 143 * parser will report the type as "NMTOKEN".</p> 144 * 145 * @param index The attribute index (zero-based). 146 * @return The attribute's type as a string, or null if the 147 * index is out of range. 148 * @see #getLength 149 */ getType(int index)150 public abstract String getType (int index); 151 152 153 /** 154 * Look up an attribute's value by index. 155 * 156 * <p>If the attribute value is a list of tokens (IDREFS, 157 * ENTITIES, or NMTOKENS), the tokens will be concatenated 158 * into a single string with each token separated by a 159 * single space.</p> 160 * 161 * @param index The attribute index (zero-based). 162 * @return The attribute's value as a string, or null if the 163 * index is out of range. 164 * @see #getLength 165 */ getValue(int index)166 public abstract String getValue (int index); 167 168 169 170 //////////////////////////////////////////////////////////////////// 171 // Name-based query. 172 //////////////////////////////////////////////////////////////////// 173 174 175 /** 176 * Look up the index of an attribute by Namespace name. 177 * 178 * @param uri The Namespace URI, or the empty string if 179 * the name has no Namespace URI. 180 * @param localName The attribute's local name. 181 * @return The index of the attribute, or -1 if it does not 182 * appear in the list. 183 */ getIndex(String uri, String localName)184 public int getIndex (String uri, String localName); 185 186 187 /** 188 * Look up the index of an attribute by XML qualified (prefixed) name. 189 * 190 * @param qName The qualified (prefixed) name. 191 * @return The index of the attribute, or -1 if it does not 192 * appear in the list. 193 */ getIndex(String qName)194 public int getIndex (String qName); 195 196 197 /** 198 * Look up an attribute's type by Namespace name. 199 * 200 * <p>See {@link #getType(int) getType(int)} for a description 201 * of the possible types.</p> 202 * 203 * @param uri The Namespace URI, or the empty String if the 204 * name has no Namespace URI. 205 * @param localName The local name of the attribute. 206 * @return The attribute type as a string, or null if the 207 * attribute is not in the list or if Namespace 208 * processing is not being performed. 209 */ getType(String uri, String localName)210 public abstract String getType (String uri, String localName); 211 212 213 /** 214 * Look up an attribute's type by XML qualified (prefixed) name. 215 * 216 * <p>See {@link #getType(int) getType(int)} for a description 217 * of the possible types.</p> 218 * 219 * @param qName The XML qualified name. 220 * @return The attribute type as a string, or null if the 221 * attribute is not in the list or if qualified names 222 * are not available. 223 */ getType(String qName)224 public abstract String getType (String qName); 225 226 227 /** 228 * Look up an attribute's value by Namespace name. 229 * 230 * <p>See {@link #getValue(int) getValue(int)} for a description 231 * of the possible values.</p> 232 * 233 * @param uri The Namespace URI, or the empty String if the 234 * name has no Namespace URI. 235 * @param localName The local name of the attribute. 236 * @return The attribute value as a string, or null if the 237 * attribute is not in the list. 238 */ getValue(String uri, String localName)239 public abstract String getValue (String uri, String localName); 240 241 242 /** 243 * Look up an attribute's value by XML qualified (prefixed) name. 244 * 245 * <p>See {@link #getValue(int) getValue(int)} for a description 246 * of the possible values.</p> 247 * 248 * @param qName The XML qualified name. 249 * @return The attribute value as a string, or null if the 250 * attribute is not in the list or if qualified names 251 * are not available. 252 */ getValue(String qName)253 public abstract String getValue (String qName); 254 255 } 256 257 // end of Attributes.java 258