LocalNameFunction


1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/LocalNameFunction.java,v 1.12 2005/06/26 16:07:23 elharo Exp $
3    * $Revision: 1.12 $
4    * $Date: 2005/06/26 16:07:23 $
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 1.12 2005/06/26 16:07:23 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 
185
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags