1 /*
2 * $Header$
3 * $Revision$
4 * $Date$
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 * $Id$
46 */
47
48 package org.jaxen.function;
49
50 import java.util.List;
51
52 import org.jaxen.Context;
53 import org.jaxen.Function;
54 import org.jaxen.FunctionCallException;
55 import org.jaxen.Navigator;
56
57 /**
58 * <p><b>4.2</b> <code><i>boolean</i> contains(<i>string</i>,<i>string</i>)</code></p>
59 *
60 * <blockquote cite="http://www.w3.org/TR/xpath">
61 * The <b>contains</b> function returns true if the first argument
62 * string contains the second argument string, and otherwise returns false.
63 * </blockquote>
64 *
65 * @author bob mcwhirter (bob @ werken.com)
66 *
67 * @see <a href="https://www.w3.org/TR/xpath#function-contains">Section 4.2 of the XPath Specification</a>
68 */
69 public class ContainsFunction implements Function
70 {
71
72 /**
73 * Create a new <code>ContainsFunction</code> object.
74 */
75 public ContainsFunction() {}
76
77 /**
78 * <p>
79 * Returns true if the string-value of the
80 * first item in <code>args</code> contains string-value of the second
81 * item; false otherwise.
82 * If necessary one or both items are converted to a string as if by the XPath
83 * <code>string()</code> function.
84 * </p>
85 *
86 * @param context the context at the point in the
87 * expression when the function is called
88 * @param args a list containing exactly two items
89 *
90 * @return the result of evaluating the function;
91 * <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
92 *
93 * @throws FunctionCallException if <code>args</code> does not have exactly two items
94 */
95 public Object call(Context context,
96 List args) throws FunctionCallException
97 {
98 if (args.size() == 2)
99 {
100 return evaluate(args.get(0),
101 args.get(1),
102 context.getNavigator() );
103 }
104
105 throw new FunctionCallException("contains() requires two arguments.");
106 }
107
108 /**
109 * <p>Returns true if the first string contains the second string; false otherwise.
110 * If necessary one or both arguments are converted to a string as if by the XPath
111 * <code>string()</code> function.
112 * </p>
113 *
114 * @param strArg the containing string
115 * @param matchArg the contained string
116 * @param nav used to calculate the string-values of the first two arguments
117 *
118 * @return <code>Boolean.TRUE</code> if true if the first string contains
119 * the second string; <code>Boolean.FALSE</code> otherwise.
120 */
121 public static Boolean evaluate(Object strArg,
122 Object matchArg,
123 Navigator nav)
124 {
125 String str = StringFunction.evaluate( strArg,
126 nav );
127
128 String match = StringFunction.evaluate( matchArg,
129 nav );
130
131 return ( ( str.indexOf(match) >= 0)
132 ? Boolean.TRUE
133 : Boolean.FALSE
134 );
135 }
136 }