1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/LocalNameFunction.java,v 1.13 2005/06/28 13:44:45 elharo Exp $
3 * $Revision: 1.13 $
4 * $Date: 2005/06/28 13:44:45 $
5 *
6 * ====================================================================
7 *
8 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer.
17 *
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions, and the disclaimer that follows
20 * these conditions in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * 3. The name "Jaxen" must not be used to endorse or promote products
24 * derived from this software without prior written permission. For
25 * written permission, please contact license@jaxen.org.
26 *
27 * 4. Products derived from this software may not be called "Jaxen", nor
28 * may "Jaxen" appear in their name, without prior written permission
29 * from the Jaxen Project Management (pm@jaxen.org).
30 *
31 * In addition, we request (but do not require) that you include in the
32 * end-user documentation provided with the redistribution and/or in the
33 * software itself an acknowledgement equivalent to the following:
34 * "This product includes software developed by the
35 * Jaxen Project <http://www.jaxen.org/>."
36 * Alternatively, the acknowledgment may be graphical using the logos
37 * available at http://www.jaxen.org/
38 *
39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * ====================================================================
53 * This software consists of voluntary contributions made by many
54 * individuals on behalf of the Jaxen Project and was originally
55 * created by bob mcwhirter <bob@werken.com> and
56 * James Strachan <jstrachan@apache.org>. For more information on the
57 * Jaxen Project, please see <http://www.jaxen.org/>.
58 *
59 * $Id: LocalNameFunction.java,v 1.13 2005/06/28 13:44:45 elharo Exp $
60 */
61
62
63 package org.jaxen.function;
64
65 import java.util.List;
66
67 import org.jaxen.Context;
68 import org.jaxen.Function;
69 import org.jaxen.FunctionCallException;
70 import org.jaxen.Navigator;
71
72 /***
73 * <p><b>4.1</b> <code><i>string</i> local-name(<i>node-set?</i>)</code></p>
74 *
75 *
76 * <blockquote src="http://www.w3.org/TR/xpath">
77 * The <b>local-name</b> function returns the local part of the
78 * expanded-name of the node in the argument node-set that is first in document order.
79 * If the argument node-set is empty or the first node has no expanded-name, an
80 * empty string is returned. If the argument is omitted, it defaults to a node-set with the context node as its only member.
81 *
82 * </blockquote>
83 *
84 * @author bob mcwhirter (bob @ werken.com)
85 * @see <a href="http://www.w3.org/TR/xpath#function-local-name" target="_top">Section 4.1 of the XPath Specification</a>
86 */
87 public class LocalNameFunction implements Function
88 {
89
90 /***
91 * Create a new <code>LocalNameFunction</code> object.
92 */
93 public LocalNameFunction() {}
94
95 /***
96 * Returns the local-name of the specified node or the context node if
97 * no arguments are provided.
98 *
99 * @param context the context at the point in the
100 * expression where the function is called
101 * @param args a <code>List</code> containing zero or one items
102 *
103 * @return a <code>String</code> containing the local-name
104 *
105 * @throws FunctionCallException if <code>args</code> has more than one item
106 */
107 public Object call(Context context,
108 List args) throws FunctionCallException
109 {
110 if ( args.size() == 0 )
111 {
112 return evaluate( context.getNodeSet(),
113 context.getNavigator() );
114 }
115
116 if ( args.size() == 1 )
117 {
118 return evaluate( args,
119 context.getNavigator() );
120 }
121
122 throw new FunctionCallException( "local-name() requires zero or one argument." );
123 }
124
125 /***
126 * Returns the local-name of <code>list.get(0)</code>
127 *
128 * @param list a list of nodes
129 * @param nav the <code>Navigator</code> used to retrieve the local name
130 *
131 * @return the local-name of <code>list.get(0)</code>
132 *
133 * @throws FunctionCallException if <code>list.get(0)</code> is not a node
134 */
135 public static String evaluate(List list,
136 Navigator nav) throws FunctionCallException
137 {
138 if ( ! list.isEmpty() )
139 {
140 Object first = list.get(0);
141
142 if (first instanceof List)
143 {
144 return evaluate( (List) first,
145 nav );
146 }
147 else if ( nav.isElement( first ) )
148 {
149 return nav.getElementName( first );
150 }
151 else if ( nav.isAttribute( first ) )
152 {
153 return nav.getAttributeName( first );
154 }
155 else if ( nav.isProcessingInstruction( first ) )
156 {
157 return nav.getProcessingInstructionTarget( first );
158 }
159 else if ( nav.isNamespace( first ) )
160 {
161 return nav.getNamespacePrefix( first );
162 }
163 else if ( nav.isDocument( first ) )
164 {
165 return "";
166 }
167 else if ( nav.isComment( first ) )
168 {
169 return "";
170 }
171 else if ( nav.isText( first ) )
172 {
173 return "";
174 }
175 else {
176 throw new FunctionCallException("The argument to the local-name function must be a node-set");
177 }
178 }
179
180 return "";
181 }
182
183 }
184