1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ext/EvaluateFunction.java,v 1.10 2006/02/05 21:47:42 elharo Exp $
3 * $Revision: 1.10 $
4 * $Date: 2006/02/05 21:47:42 $
5 *
6 * ====================================================================
7 *
8 * Copyright 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 are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id: EvaluateFunction.java,v 1.10 2006/02/05 21:47:42 elharo Exp $
46 */
47
48 package org.jaxen.function.ext;
49
50 import java.util.Collections;
51 import java.util.List;
52
53 import org.jaxen.Context;
54 import org.jaxen.ContextSupport;
55 import org.jaxen.Function;
56 import org.jaxen.FunctionCallException;
57 import org.jaxen.Navigator;
58 import org.jaxen.XPath;
59 import org.jaxen.function.StringFunction;
60
61 /***
62 * <code><i>node-set</i> evaluate(<i>string</i>)</code>
63 *
64 * @author Erwin Bolwidt (ejb @ klomp.org)
65 */
66 public class EvaluateFunction implements Function
67 {
68 public Object call( Context context, List args )
69 throws FunctionCallException
70 {
71 if ( args.size() == 1 ) {
72 return evaluate( context, args.get(0));
73 }
74
75 throw new FunctionCallException( "evaluate() requires one argument" );
76 }
77
78 public static List evaluate (Context context, Object arg)
79 throws FunctionCallException
80 {
81 List contextNodes = context.getNodeSet();
82
83 if (contextNodes.size() == 0)
84 return Collections.EMPTY_LIST;
85
86 Navigator nav = context.getNavigator();
87
88 String xpathString;
89 if ( arg instanceof String )
90 xpathString = (String)arg;
91 else
92 xpathString = StringFunction.evaluate(arg, nav);
93
94 try {
95 XPath xpath = nav.parseXPath(xpathString);
96 ContextSupport support = context.getContextSupport();
97 xpath.setVariableContext( support.getVariableContext() );
98 xpath.setFunctionContext( support.getFunctionContext() );
99 xpath.setNamespaceContext( support.getNamespaceContext() );
100 return xpath.selectNodes( context.duplicate() );
101 }
102 catch ( org.jaxen.saxpath.SAXPathException e ) {
103 throw new FunctionCallException(e.toString());
104 }
105 }
106 }
107