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  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
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  25 
  26 // Attributes.java - attribute list with Namespace support
  27 // http://www.saxproject.org
  28 // Written by David Megginson
  29 // NO WARRANTY!  This class is in the public domain.
  30 // $Id: Attributes.java,v 1.2 2004/11/03 22:44:51 jsuttor Exp $
  31 
  32 package org.xml.sax;
  33 
  34 
  35 /**
  36  * Interface for a list of XML attributes.
  37  *
  38  * <blockquote>
  39  * <em>This module, both source code and documentation, is in the
  40  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  41  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  42  * for further information.
  43  * </blockquote>
  44  *
  45  * <p>This interface allows access to a list of attributes in
  46  * three different ways:</p>
  47  *
  48  * <ol>
  49  * <li>by attribute index;</li>
  50  * <li>by Namespace-qualified name; or</li>
  51  * <li>by qualified (prefixed) name.</li>
  52  * </ol>
  53  *
  54  * <p>The list will not contain attributes that were declared
  55  * #IMPLIED but not specified in the start tag.  It will also not
  56  * contain attributes used as Namespace declarations (xmlns*) unless
  57  * the <code>http://xml.org/sax/features/namespace-prefixes</code>
  58  * feature is set to <var>true</var> (it is <var>false</var> by
  59  * default).
  60  * Because SAX2 conforms to the original "Namespaces in XML"
  61  * recommendation, it normally does not
  62  * give namespace declaration attributes a namespace URI.
  63  * </p>
  64  *
  65  * <p>Some SAX2 parsers may support using an optional feature flag
  66  * (<code>http://xml.org/sax/features/xmlns-uris</code>) to request
  67  * that those attributes be given URIs, conforming to a later
  68  * backwards-incompatible revision of that recommendation.  (The
  69  * attribute's "local name" will be the prefix, or "xmlns" when
  70  * defining a default element namespace.)  For portability, handler
  71  * code should always resolve that conflict, rather than requiring
  72  * parsers that can change the setting of that feature flag.  </p>
  73  *
  74  * <p>If the namespace-prefixes feature (see above) is
  75  * <var>false</var>, access by qualified name may not be available; if
  76  * the <code>http://xml.org/sax/features/namespaces</code> feature is
  77  * <var>false</var>, access by Namespace-qualified names may not be
  78  * available.</p>
  79  *
  80  * <p>This interface replaces the now-deprecated SAX1 {@link
  81  * org.xml.sax.AttributeList AttributeList} interface, which does not
  82  * contain Namespace support.  In addition to Namespace support, it
  83  * adds the <var>getIndex</var> methods (below).</p>
  84  *
  85  * <p>The order of attributes in the list is unspecified, and will
  86  * vary from implementation to implementation.</p>
  87  *
  88  * @since 1.4, SAX 2.0
  89  * @author David Megginson
  90  * @see org.xml.sax.helpers.AttributesImpl
  91  * @see org.xml.sax.ext.DeclHandler#attributeDecl
  92  */
  93 public interface Attributes
  94 {
  95 
  96 
  97     ////////////////////////////////////////////////////////////////////
  98     // Indexed access.
  99     ////////////////////////////////////////////////////////////////////
 100 
 101 
 102     /**
 103      * Return the number of attributes in the list.
 104      *
 105      * <p>Once you know the number of attributes, you can iterate
 106      * through the list.</p>
 107      *
 108      * @return The number of attributes in the list.
 109      * @see #getURI(int)
 110      * @see #getLocalName(int)
 111      * @see #getQName(int)
 112      * @see #getType(int)
 113      * @see #getValue(int)
 114      */
 115     public abstract int getLength ();
 116 
 117 
 118     /**
 119      * Look up an attribute's Namespace URI by index.
 120      *
 121      * @param index The attribute index (zero-based).
 122      * @return The Namespace URI, or the empty string if none
 123      *         is available, or null if the index is out of
 124      *         range.
 125      * @see #getLength
 126      */
 127     public abstract String getURI (int index);
 128 
 129 
 130     /**
 131      * Look up an attribute's local name by index.
 132      *
 133      * @param index The attribute index (zero-based).
 134      * @return The local name, or the empty string if Namespace
 135      *         processing is not being performed, or null
 136      *         if the index is out of range.
 137      * @see #getLength
 138      */
 139     public abstract String getLocalName (int index);
 140 
 141 
 142     /**
 143      * Look up an attribute's XML qualified (prefixed) name by index.
 144      *
 145      * @param index The attribute index (zero-based).
 146      * @return The XML qualified name, or the empty string
 147      *         if none is available, or null if the index
 148      *         is out of range.
 149      * @see #getLength
 150      */
 151     public abstract String getQName (int index);
 152 
 153 
 154     /**
 155      * Look up an attribute's type by index.
 156      *
 157      * <p>The attribute type is one of the strings "CDATA", "ID",
 158      * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES",
 159      * or "NOTATION" (always in upper case).</p>
 160      *
 161      * <p>If the parser has not read a declaration for the attribute,
 162      * or if the parser does not report attribute types, then it must
 163      * return the value "CDATA" as stated in the XML 1.0 Recommendation
 164      * (clause 3.3.3, "Attribute-Value Normalization").</p>
 165      *
 166      * <p>For an enumerated attribute that is not a notation, the
 167      * parser will report the type as "NMTOKEN".</p>
 168      *
 169      * @param index The attribute index (zero-based).
 170      * @return The attribute's type as a string, or null if the
 171      *         index is out of range.
 172      * @see #getLength
 173      */
 174     public abstract String getType (int index);
 175 
 176 
 177     /**
 178      * Look up an attribute's value by index.
 179      *
 180      * <p>If the attribute value is a list of tokens (IDREFS,
 181      * ENTITIES, or NMTOKENS), the tokens will be concatenated
 182      * into a single string with each token separated by a
 183      * single space.</p>
 184      *
 185      * @param index The attribute index (zero-based).
 186      * @return The attribute's value as a string, or null if the
 187      *         index is out of range.
 188      * @see #getLength
 189      */
 190     public abstract String getValue (int index);
 191 
 192 
 193 
 194     ////////////////////////////////////////////////////////////////////
 195     // Name-based query.
 196     ////////////////////////////////////////////////////////////////////
 197 
 198 
 199     /**
 200      * Look up the index of an attribute by Namespace name.
 201      *
 202      * @param uri The Namespace URI, or the empty string if
 203      *        the name has no Namespace URI.
 204      * @param localName The attribute's local name.
 205      * @return The index of the attribute, or -1 if it does not
 206      *         appear in the list.
 207      */
 208     public int getIndex (String uri, String localName);
 209 
 210 
 211     /**
 212      * Look up the index of an attribute by XML qualified (prefixed) name.
 213      *
 214      * @param qName The qualified (prefixed) name.
 215      * @return The index of the attribute, or -1 if it does not
 216      *         appear in the list.
 217      */
 218     public int getIndex (String qName);
 219 
 220 
 221     /**
 222      * Look up an attribute's type by Namespace name.
 223      *
 224      * <p>See {@link #getType(int) getType(int)} for a description
 225      * of the possible types.</p>
 226      *
 227      * @param uri The Namespace URI, or the empty String if the
 228      *        name has no Namespace URI.
 229      * @param localName The local name of the attribute.
 230      * @return The attribute type as a string, or null if the
 231      *         attribute is not in the list or if Namespace
 232      *         processing is not being performed.
 233      */
 234     public abstract String getType (String uri, String localName);
 235 
 236 
 237     /**
 238      * Look up an attribute's type by XML qualified (prefixed) name.
 239      *
 240      * <p>See {@link #getType(int) getType(int)} for a description
 241      * of the possible types.</p>
 242      *
 243      * @param qName The XML qualified name.
 244      * @return The attribute type as a string, or null if the
 245      *         attribute is not in the list or if qualified names
 246      *         are not available.
 247      */
 248     public abstract String getType (String qName);
 249 
 250 
 251     /**
 252      * Look up an attribute's value by Namespace name.
 253      *
 254      * <p>See {@link #getValue(int) getValue(int)} for a description
 255      * of the possible values.</p>
 256      *
 257      * @param uri The Namespace URI, or the empty String if the
 258      *        name has no Namespace URI.
 259      * @param localName The local name of the attribute.
 260      * @return The attribute value as a string, or null if the
 261      *         attribute is not in the list.
 262      */
 263     public abstract String getValue (String uri, String localName);
 264 
 265 
 266     /**
 267      * Look up an attribute's value by XML qualified (prefixed) name.
 268      *
 269      * <p>See {@link #getValue(int) getValue(int)} for a description
 270      * of the possible values.</p>
 271      *
 272      * @param qName The XML qualified name.
 273      * @return The attribute value as a string, or null if the
 274      *         attribute is not in the list or if qualified names
 275      *         are not available.
 276      */
 277     public abstract String getValue (String qName);
 278 
 279 }
 280 
 281 // end of Attributes.java