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1   // SAX Attribute List Interface.
2   // http://www.saxproject.org
3   // No warranty; no copyright -- use this as you will.
4   // $Id: AttributeList.java,v 1.4 2004/03/19 20:17:54 maartenc Exp $
5   
6   package org.xml.sax;
7   
8   /***
9    * Interface for an element's attribute specifications.
10   *
11   * <blockquote>
12   * <em>This module, both source code and documentation, is in the
13   * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
14   * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
15   * for further information.
16   * </blockquote>
17   *
18   * <p>This is the original SAX1 interface for reporting an element's
19   * attributes.  Unlike the new {@link org.xml.sax.Attributes Attributes}
20   * interface, it does not support Namespace-related information.</p>
21   *
22   * <p>When an attribute list is supplied as part of a
23   * {@link org.xml.sax.DocumentHandler#startElement startElement}
24   * event, the list will return valid results only during the
25   * scope of the event; once the event handler returns control
26   * to the parser, the attribute list is invalid.  To save a
27   * persistent copy of the attribute list, use the SAX1
28   * {@link org.xml.sax.helpers.AttributeListImpl AttributeListImpl}
29   * helper class.</p>
30   *
31   * <p>An attribute list includes only attributes that have been
32   * specified or defaulted: #IMPLIED attributes will not be included.</p>
33   *
34   * <p>There are two ways for the SAX application to obtain information
35   * from the AttributeList.  First, it can iterate through the entire
36   * list:</p>
37   *
38   * <pre>
39   * public void startElement (String name, AttributeList atts) {
40   *   for (int i = 0; i < atts.getLength(); i++) {
41   *     String name = atts.getName(i);
42   *     String type = atts.getType(i);
43   *     String value = atts.getValue(i);
44   *     [...]
45   *   }
46   * }
47   * </pre>
48   *
49   * <p>(Note that the result of getLength() will be zero if there
50   * are no attributes.)
51   *
52   * <p>As an alternative, the application can request the value or
53   * type of specific attributes:</p>
54   *
55   * <pre>
56   * public void startElement (String name, AttributeList atts) {
57   *   String identifier = atts.getValue("id");
58   *   String label = atts.getValue("label");
59   *   [...]
60   * }
61   * </pre>
62   *
63   * @deprecated This interface has been replaced by the SAX2
64   *             {@link org.xml.sax.Attributes Attributes}
65   *             interface, which includes Namespace support.
66   * @since SAX 1.0
67   * @author David Megginson
68   * @version 2.0.1 (sax2r2)
69   * @see org.xml.sax.DocumentHandler#startElement startElement
70   * @see org.xml.sax.helpers.AttributeListImpl AttributeListImpl
71   */
72  public interface AttributeList {
73  
74  
75      ////////////////////////////////////////////////////////////////////
76      // Iteration methods.
77      ////////////////////////////////////////////////////////////////////
78      
79  
80      /***
81       * Return the number of attributes in this list.
82       *
83       * <p>The SAX parser may provide attributes in any
84       * arbitrary order, regardless of the order in which they were
85       * declared or specified.  The number of attributes may be
86       * zero.</p>
87       *
88       * @return The number of attributes in the list.  
89       */
90      public abstract int getLength ();
91      
92      
93      /***
94       * Return the name of an attribute in this list (by position).
95       *
96       * <p>The names must be unique: the SAX parser shall not include the
97       * same attribute twice.  Attributes without values (those declared
98       * #IMPLIED without a value specified in the start tag) will be
99       * 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 i The index of the attribute in the list.
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