001    // SAX Attribute List Interface.
002    // http://www.saxproject.org
003    // No warranty; no copyright -- use this as you will.
004    // $Id: AttributeList.java,v 1.1 2004/12/23 22:38:42 mark Exp $
005    
006    package org.xml.sax;
007    
008    /**
009     * Interface for an element's attribute specifications.
010     *
011     * <blockquote>
012     * <em>This module, both source code and documentation, is in the
013     * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
014     * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
015     * for further information.
016     * </blockquote>
017     *
018     * <p>This is the original SAX1 interface for reporting an element's
019     * attributes.  Unlike the new {@link org.xml.sax.Attributes Attributes}
020     * interface, it does not support Namespace-related information.</p>
021     *
022     * <p>When an attribute list is supplied as part of a
023     * {@link org.xml.sax.DocumentHandler#startElement startElement}
024     * event, the list will return valid results only during the
025     * scope of the event; once the event handler returns control
026     * to the parser, the attribute list is invalid.  To save a
027     * persistent copy of the attribute list, use the SAX1
028     * {@link org.xml.sax.helpers.AttributeListImpl AttributeListImpl}
029     * helper class.</p>
030     *
031     * <p>An attribute list includes only attributes that have been
032     * specified or defaulted: #IMPLIED attributes will not be included.</p>
033     *
034     * <p>There are two ways for the SAX application to obtain information
035     * from the AttributeList.  First, it can iterate through the entire
036     * list:</p>
037     *
038     * <pre>
039     * public void startElement (String name, AttributeList atts) {
040     *   for (int i = 0; i < atts.getLength(); i++) {
041     *     String name = atts.getName(i);
042     *     String type = atts.getType(i);
043     *     String value = atts.getValue(i);
044     *     [...]
045     *   }
046     * }
047     * </pre>
048     *
049     * <p>(Note that the result of getLength() will be zero if there
050     * are no attributes.)
051     *
052     * <p>As an alternative, the application can request the value or
053     * type of specific attributes:</p>
054     *
055     * <pre>
056     * public void startElement (String name, AttributeList atts) {
057     *   String identifier = atts.getValue("id");
058     *   String label = atts.getValue("label");
059     *   [...]
060     * }
061     * </pre>
062     *
063     * @deprecated This interface has been replaced by the SAX2
064     *             {@link org.xml.sax.Attributes Attributes}
065     *             interface, which includes Namespace support.
066     * @since SAX 1.0
067     * @author David Megginson
068     * @version 2.0.1 (sax2r2)
069     * @see org.xml.sax.DocumentHandler#startElement startElement
070     * @see org.xml.sax.helpers.AttributeListImpl AttributeListImpl
071     */
072    public interface AttributeList {
073    
074    
075        ////////////////////////////////////////////////////////////////////
076        // Iteration methods.
077        ////////////////////////////////////////////////////////////////////
078    
079    
080        /**
081         * Return the number of attributes in this list.
082         *
083         * <p>The SAX parser may provide attributes in any
084         * arbitrary order, regardless of the order in which they were
085         * declared or specified.  The number of attributes may be
086         * zero.</p>
087         *
088         * @return The number of attributes in the list.
089         */
090        public abstract int getLength ();
091    
092    
093        /**
094         * Return the name of an attribute in this list (by position).
095         *
096         * <p>The names must be unique: the SAX parser shall not include the
097         * same attribute twice.  Attributes without values (those declared
098         * #IMPLIED without a value specified in the start tag) will be
099         * omitted from the list.</p>
100         *
101         * <p>If the attribute name has a namespace prefix, the prefix
102         * will still be attached.</p>
103         *
104         * @param i The index of the attribute in the list (starting at 0).
105         * @return The name of the indexed attribute, or null
106         *         if the index is out of range.
107         * @see #getLength
108         */
109        public abstract String getName (int i);
110    
111    
112        /**
113         * Return the type of an attribute in the list (by position).
114         *
115         * <p>The attribute type is one of the strings "CDATA", "ID",
116         * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES",
117         * or "NOTATION" (always in upper case).</p>
118         *
119         * <p>If the parser has not read a declaration for the attribute,
120         * or if the parser does not report attribute types, then it must
121         * return the value "CDATA" as stated in the XML 1.0 Recommentation
122         * (clause 3.3.3, "Attribute-Value Normalization").</p>
123         *
124         * <p>For an enumerated attribute that is not a notation, the
125         * parser will report the type as "NMTOKEN".</p>
126         *
127         * @param i The index of the attribute in the list (starting at 0).
128         * @return The attribute type as a string, or
129         *         null if the index is out of range.
130         * @see #getLength
131         * @see #getType(java.lang.String)
132         */
133        public abstract String getType (int i);
134    
135    
136        /**
137         * Return the value of an attribute in the list (by position).
138         *
139         * <p>If the attribute value is a list of tokens (IDREFS,
140         * ENTITIES, or NMTOKENS), the tokens will be concatenated
141         * into a single string separated by whitespace.</p>
142         *
143         * @param i The index of the attribute in the list (starting at 0).
144         * @return The attribute value as a string, or
145         *         null if the index is out of range.
146         * @see #getLength
147         * @see #getValue(java.lang.String)
148         */
149        public abstract String getValue (int i);
150    
151    
152    
153        ////////////////////////////////////////////////////////////////////
154        // Lookup methods.
155        ////////////////////////////////////////////////////////////////////
156    
157    
158        /**
159         * Return the type of an attribute in the list (by name).
160         *
161         * <p>The return value is the same as the return value for
162         * getType(int).</p>
163         *
164         * <p>If the attribute name has a namespace prefix in the document,
165         * the application must include the prefix here.</p>
166         *
167         * @param name The name of the attribute.
168         * @return The attribute type as a string, or null if no
169         *         such attribute exists.
170         * @see #getType(int)
171         */
172        public abstract String getType (String name);
173    
174    
175        /**
176         * Return the value of an attribute in the list (by name).
177         *
178         * <p>The return value is the same as the return value for
179         * getValue(int).</p>
180         *
181         * <p>If the attribute name has a namespace prefix in the document,
182         * the application must include the prefix here.</p>
183         *
184         * @param name the name of the attribute to return
185         * @return The attribute value as a string, or null if
186         *         no such attribute exists.
187         * @see #getValue(int)
188         */
189        public abstract String getValue (String name);
190    
191    }
192    
193    // end of AttributeList.java