libjava/org/xml/sax/Attributes.java

   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
   6 // $Id: Attributes.java,v 1.5.2.4 2002/01/29 21:34:14 dbrownell Exp $
   7
   8
   9 package org.xml.sax;
  10
  11
  12 /**
  13  * Interface for a list of XML attributes.
  14  *
  15  * <blockquote>
  16  * <em>This module, both source code and documentation, is in the
  17  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  18  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  19  * for further information.
  20  * </blockquote>
  21  *
  22  * <p>This interface allows access to a list of attributes in
  23  * three different ways:</p>
  24  *
  25  * <ol>
  26  * <li>by attribute index;</li>
  27  * <li>by Namespace-qualified name; or</li>
  28  * <li>by qualified (prefixed) name.</li>
  29  * </ol>
  30  *
  31  * <p>The list will not contain attributes that were declared
  32  * #IMPLIED but not specified in the start tag.  It will also not
  33  * contain attributes used as Namespace declarations (xmlns*) unless
  34  * the <code>http://xml.org/sax/features/namespace-prefixes</code>
  35  * feature is set to <var>true</var> (it is <var>false</var> by
  36  * default).
  37  * Because SAX2 conforms to the "Namespaces in XML" specification,
  38  * it does not give namespace declaration attributes a namespace URI.
  39  * Some other W3C specifications are in conflict with that, expecting
  40  * these declarations to be in a namespace.
  41  * Handler code may need to resolve that conflict.
  42  * </p>
  43  *
  44  * <p>If the namespace-prefixes feature (see above) is <var>false</var>,
  45  * access by qualified name may not be available; if the
  46  * <code>http://xml.org/sax/features/namespaces</code>
  47  * feature is <var>false</var>, access by Namespace-qualified names
  48  * may not be available.</p>
  49  *
  50  * <p>This interface replaces the now-deprecated SAX1 {@link
  51  * org.xml.sax.AttributeList AttributeList} interface, which does not
  52  * contain Namespace support.  In addition to Namespace support, it
  53  * adds the <var>getIndex</var> methods (below).</p>
  54  *
  55  * <p>The order of attributes in the list is unspecified, and will
  56  * vary from implementation to implementation.</p>
  57  *
  58  * @since SAX 2.0
  59  * @author David Megginson
  60  * @version 2.0.1 (sax2r2)
  61  * @see org.xml.sax.helpers.AttributesImpl
  62  * @see org.xml.sax.ext.DeclHandler#attributeDecl
  63  */
  64 public interface Attributes
  65 {
  66
  67 \f
  68     ////////////////////////////////////////////////////////////////////
  69     // Indexed access.
  70     ////////////////////////////////////////////////////////////////////
  71
  72
  73     /**
  74      * Return the number of attributes in the list.
  75      *
  76      * <p>Once you know the number of attributes, you can iterate
  77      * through the list.</p>
  78      *
  79      * @return The number of attributes in the list.
  80      * @see #getURI(int)
  81      * @see #getLocalName(int)
  82      * @see #getQName(int)
  83      * @see #getType(int)
  84      * @see #getValue(int)
  85      */
  86     public abstract int getLength ();
  87
  88
  89     /**
  90      * Look up an attribute's Namespace URI by index.
  91      *
  92      * @param index The attribute index (zero-based).
  93      * @return The Namespace URI, or the empty string if none
  94      *         is available, or null if the index is out of
  95      *         range.
  96      * @see #getLength
  97      */
  98     public abstract String getURI (int index);
  99
 100
 101     /**
 102      * Look up an attribute's local name by index.
 103      *
 104      * @param index The attribute index (zero-based).
 105      * @return The local name, or the empty string if Namespace
 106      *         processing is not being performed, or null
 107      *         if the index is out of range.
 108      * @see #getLength
 109      */
 110     public abstract String getLocalName (int index);
 111
 112
 113     /**
 114      * Look up an attribute's XML 1.0 qualified name by index.
 115      *
 116      * @param index The attribute index (zero-based).
 117      * @return The XML 1.0 qualified name, or the empty string
 118      *         if none is available, or null if the index
 119      *         is out of range.
 120      * @see #getLength
 121      */
 122     public abstract String getQName (int index);
 123
 124
 125     /**
 126      * Look up an attribute's type by index.
 127      *
 128      * <p>The attribute type is one of the strings "CDATA", "ID",
 129      * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES",
 130      * or "NOTATION" (always in upper case).</p>
 131      *
 132      * <p>If the parser has not read a declaration for the attribute,
 133      * or if the parser does not report attribute types, then it must
 134      * return the value "CDATA" as stated in the XML 1.0 Recommentation
 135      * (clause 3.3.3, "Attribute-Value Normalization").</p>
 136      *
 137      * <p>For an enumerated attribute that is not a notation, the
 138      * parser will report the type as "NMTOKEN".</p>
 139      *
 140      * @param index The attribute index (zero-based).
 141      * @return The attribute's type as a string, or null if the
 142      *         index is out of range.
 143      * @see #getLength
 144      */
 145     public abstract String getType (int index);
 146
 147
 148     /**
 149      * Look up an attribute's value by index.
 150      *
 151      * <p>If the attribute value is a list of tokens (IDREFS,
 152      * ENTITIES, or NMTOKENS), the tokens will be concatenated
 153      * into a single string with each token separated by a
 154      * single space.</p>
 155      *
 156      * @param index The attribute index (zero-based).
 157      * @return The attribute's value as a string, or null if the
 158      *         index is out of range.
 159      * @see #getLength
 160      */
 161     public abstract String getValue (int index);
 162
 163
 164 \f
 165     ////////////////////////////////////////////////////////////////////
 166     // Name-based query.
 167     ////////////////////////////////////////////////////////////////////
 168
 169
 170     /**
 171      * Look up the index of an attribute by Namespace name.
 172      *
 173      * @param uri The Namespace URI, or the empty string if
 174      *        the name has no Namespace URI.
 175      * @param localName The attribute's local name.
 176      * @return The index of the attribute, or -1 if it does not
 177      *         appear in the list.
 178      */
 179     public int getIndex (String uri, String localName);
 180
 181
 182     /**
 183      * Look up the index of an attribute by XML 1.0 qualified name.
 184      *
 185      * @param qName The qualified (prefixed) name.
 186      * @return The index of the attribute, or -1 if it does not
 187      *         appear in the list.
 188      */
 189     public int getIndex (String qName);
 190
 191
 192     /**
 193      * Look up an attribute's type by Namespace name.
 194      *
 195      * <p>See {@link #getType(int) getType(int)} for a description
 196      * of the possible types.</p>
 197      *
 198      * @param uri The Namespace URI, or the empty String if the
 199      *        name has no Namespace URI.
 200      * @param localName The local name of the attribute.
 201      * @return The attribute type as a string, or null if the
 202      *         attribute is not in the list or if Namespace
 203      *         processing is not being performed.
 204      */
 205     public abstract String getType (String uri, String localName);
 206
 207
 208     /**
 209      * Look up an attribute's type by XML 1.0 qualified name.
 210      *
 211      * <p>See {@link #getType(int) getType(int)} for a description
 212      * of the possible types.</p>
 213      *
 214      * @param qName The XML 1.0 qualified name.
 215      * @return The attribute type as a string, or null if the
 216      *         attribute is not in the list or if qualified names
 217      *         are not available.
 218      */
 219     public abstract String getType (String qName);
 220
 221
 222     /**
 223      * Look up an attribute's value by Namespace name.
 224      *
 225      * <p>See {@link #getValue(int) getValue(int)} for a description
 226      * of the possible values.</p>
 227      *
 228      * @param uri The Namespace URI, or the empty String if the
 229      *        name has no Namespace URI.
 230      * @param localName The local name of the attribute.
 231      * @return The attribute value as a string, or null if the
 232      *         attribute is not in the list.
 233      */
 234     public abstract String getValue (String uri, String localName);
 235
 236
 237     /**
 238      * Look up an attribute's value by XML 1.0 qualified name.
 239      *
 240      * <p>See {@link #getValue(int) getValue(int)} for a description
 241      * of the possible values.</p>
 242      *
 243      * @param qName The XML 1.0 qualified name.
 244      * @return The attribute value 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 getValue (String qName);
 249
 250 }
 251
 252 // end of Attributes.java