1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ext/EvaluateFunction.java,v 1.8 2005/01/26 11:55:40 elharo Exp $
3 * $Revision: 1.8 $
4 * $Date: 2005/01/26 11:55:40 $
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: EvaluateFunction.java,v 1.8 2005/01/26 11:55:40 elharo Exp $
60 */
61
62 package org.jaxen.function.ext;
63
64 import java.util.Collections;
65 import java.util.List;
66
67 import org.jaxen.Context;
68 import org.jaxen.ContextSupport;
69 import org.jaxen.Function;
70 import org.jaxen.FunctionCallException;
71 import org.jaxen.Navigator;
72 import org.jaxen.XPath;
73 import org.jaxen.function.StringFunction;
74
75 /***
76 * <code><i>node-set</i> evaluate(<i>string</i>)</code>
77 *
78 * @author Erwin Bolwidt (ejb @ klomp.org)
79 */
80 public class EvaluateFunction implements Function
81 {
82 public Object call( Context context, List args )
83 throws FunctionCallException
84 {
85 if ( args.size() == 1 ) {
86 return evaluate( context, args.get(0));
87 }
88
89 throw new FunctionCallException( "evaluate() requires one argument" );
90 }
91
92 public static List evaluate (Context context, Object arg)
93 throws FunctionCallException
94 {
95 List contextNodes = context.getNodeSet();
96
97 if (contextNodes.size() == 0)
98 return Collections.EMPTY_LIST;
99
100 Navigator nav = context.getNavigator();
101
102 String xpathString;
103 if ( arg instanceof String )
104 xpathString = (String)arg;
105 else
106 xpathString = StringFunction.evaluate(arg, nav);
107
108 try {
109 XPath xpath = nav.parseXPath(xpathString);
110 ContextSupport support = context.getContextSupport();
111 xpath.setVariableContext( support.getVariableContext() );
112 xpath.setFunctionContext( support.getFunctionContext() );
113 xpath.setNamespaceContext( support.getNamespaceContext() );
114 return xpath.selectNodes( context.duplicate() );
115 }
116 catch ( org.jaxen.saxpath.SAXPathException e ) {
117 throw new FunctionCallException(e.toString());
118 }
119 }
120 }
121