1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ContainsFunction.java,v 1.7 2005/06/26 16:07:23 elharo Exp $
3 * $Revision: 1.7 $
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: ContainsFunction.java,v 1.7 2005/06/26 16:07:23 elharo Exp $
60 */
61
62 package org.jaxen.function;
63
64 import java.util.List;
65
66 import org.jaxen.Context;
67 import org.jaxen.Function;
68 import org.jaxen.FunctionCallException;
69 import org.jaxen.Navigator;
70
71 /***
72 * <p><b>4.2</b> <code><i>boolean</i> contains(<i>string</i>,<i>string</i>)</code>
73 *
74 * <blockquote src="http://www.w3.org/TR/xpath">
75 * The <b>contains</b> function returns true if the first argument
76 * string contains the second argument string, and otherwise returns false.
77 * </blockquote>
78 *
79 * @author bob mcwhirter (bob @ werken.com)
80 *
81 * @see <a href="http://www.w3.org/TR/xpath#function-contains">Section 4.2 of the XPath Specification</a>
82 */
83 public class ContainsFunction implements Function
84 {
85
86 /***
87 * Create a new <code>ContainsFunction</code> object.
88 */
89 public ContainsFunction() {}
90
91 /***
92 * <p>
93 * Returns true if the string-value of the
94 * first item in <code>args</code> contains string-value of the second
95 * item; false otherwise.
96 * If necessary one or both items are converted to a string as if by the XPath
97 * <code>string()</code> function.
98 * </p>
99 *
100 * @param context the context at the point in the
101 * expression when the function is called
102 * @param args a list containing exactly two items
103 *
104 * @return the result of evaluating the function;
105 * <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
106 *
107 * @throws FunctionCallException if <code>args</code> does not have exactly two items
108 */
109 public Object call(Context context,
110 List args) throws FunctionCallException
111 {
112 if (args.size() == 2)
113 {
114 return evaluate(args.get(0),
115 args.get(1),
116 context.getNavigator() );
117 }
118
119 throw new FunctionCallException("contains() requires two arguments.");
120 }
121
122 /***
123 * <p>Returns true if the first string contains the second string; false otherwise.
124 * If necessary one or both arguments are converted to a string as if by the XPath
125 * <code>string()</code> function.
126 * </p>
127 *
128 * @param strArg the containing string
129 * @param matchArg the contained string
130 * @param nav used to calculate the string-values of the first two arguments
131 *
132 * @return <code>Boolean.TRUE</code> if true if the first string contains
133 * the second string; <code>Boolean.FALSE</code> otherwise.
134 */
135 public static Boolean evaluate(Object strArg,
136 Object matchArg,
137 Navigator nav)
138 {
139 String str = StringFunction.evaluate( strArg,
140 nav );
141
142 String match = StringFunction.evaluate( matchArg,
143 nav );
144
145 return ( ( str.indexOf(match) >= 0)
146 ? Boolean.TRUE
147 : Boolean.FALSE
148 );
149 }
150 }