##### Coverage Report - org.jaxen.function.BooleanFunction

Classes in this File | Line Coverage | Branch Coverage | Complexity
BooleanFunction |
100% |
100% |
| 5.666666666666667;5.667

1 |  |
     /*
2 |  |
      * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/BooleanFunction.java,v 1.16 2005/06/28 13:44:45 elharo Exp $
3 |  |
      * $Revision: 1.16 $
4 |  |
      * $Date: 2005/06/28 13:44:45 $
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).
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      *
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: BooleanFunction.java,v 1.16 2005/06/28 13:44:45 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>
74 |  |
      * <b>4.3</b> <code><i>boolean</i> boolean(<i>object</i>)</code>
75 |  |
      * </p>
76 |  |
      *
77 |  |
      * <blockquote
78 |  |
      * src="http://www.w3.org/TR/xpath#section-Boolean-Functions">
79 |  |
      * <p>
80 |  |
      * The <b><a href="http://www.w3.org/TR/xpath#function-boolean" target="_top">boolean</a></b>
81 |  |
      * function converts its argument to a boolean as follows:
82 |  |
      * </p>
83 |  |
      *
84 |  |
      * <ul>
85 |  |
      *
86 |  |
      * <li>
87 |  |
      * <p>
88 |  |
      * a number is true if and only if it is neither positive or negative
89 |  |
      * zero nor NaN
90 |  |
      * </p>
91 |  |
      * </li>
92 |  |
      *
93 |  |
      * <li>
94 |  |
      * <p>
95 |  |
      * a node-set is true if and only if it is non-empty
96 |  |
      * </p>
97 |  |
      * </li>
98 |  |
      *
99 |  |
      * <li>
100 |  |
      * <p>
101 |  |
      * a string is true if and only if its length is non-zero
102 |  |
      * </p>
103 |  |
      * </li>
104 |  |
      *
105 |  |
      * <li>
106 |  |
      *
107 |  |
      * <p>
108 |  |
      * an object of a type other than the four basic types is converted to a
109 |  |
      * boolean in a way that is dependent on that type
110 |  |
      * </p></li></ul>
111 |  |
      * </blockquote>
112 |  |
      *
113 |  |
      * @author bob mcwhirter (bob @ werken.com)
114 |  |
      * @see <a href="http://www.w3.org/TR/xpath#function-boolean">Section 4.3 of the XPath Specification</a>
115 |  |
      */
116 |  |
     public class BooleanFunction implements Function
117 |  |
     {
118 |  |
119 |  |
120 |  |
         /**
121 |  |
          * Create a new <code>BooleanFunction</code> object.
122 |  |
          */
123 | 294 |
         public BooleanFunction() {}
124 |  |
125 |  |
         /** Convert the argument to a <code>Boolean</code>
126 |  |
          *
127 |  |
          * @param context the context at the point in the
128 |  |
          *         expression when the function is called
129 |  |
          * @param args a list with exactly one item which will be converted to a
130 |  |
          *     <code>Boolean</code>
131 |  |
          *
132 |  |
          * @return the result of evaluating the function;
133 |  |
          *     <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
134 |  |
          *
135 |  |
          * @throws FunctionCallException if <code>args</code> has more or less than one item
136 |  |
          */
137 |  |
         public Object call(Context context,
138 |  |
                            List args) throws FunctionCallException
139 |  |
         {
140 | 48 |
             if ( args.size() == 1 )
141 |  |
             {
142 | 36 |
                 return evaluate( args.get(0), context.getNavigator() );
143 |  |
             }
144 |  |
145 | 12 |
             throw new FunctionCallException("boolean() requires one argument");
146 |  |
         }
147 |  |
148 |  |
         /**
149 |  |
          * <p>Convert the argument <code>obj</code> to a <code>Boolean</code>
150 |  |
          * according to the following rules:</p>
151 |  |
          *
152 |  |
          * <ul>
153 |  |
          * <li>Lists are false if they're empty; true if they're not.</li>
154 |  |
          * <li>Booleans are false if they're false; true if they're true.</li>
155 |  |
          * <li>Strings are false if they're empty; true if they're not.</li>
156 |  |
          * <li>Numbers are false if they're 0 or NaN; true if they're not.</li>
157 |  |
          * <li>All other objects are true.</li>
158 |  |
          * </ul>
159 |  |
          *
160 |  |
          * @param obj the object to convert to a boolean
161 |  |
          * @param nav ignored
162 |  |
          *
163 |  |
          * @return <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
164 |  |
          */
165 |  |
         public static Boolean evaluate(Object obj, Navigator nav)
166 |  |
         {
167 | 21486 |
             if ( obj instanceof List )
168 |  |
             {
169 | 1302 |
                 List list = (List) obj;
170 |  |
171 |  |
                 // if it's an empty list, then we have a null node-set -> false
172 | 1302 |
                 if (list.size() == 0)
173 |  |
                 {
174 | 18 |
                     return Boolean.FALSE;
175 |  |
                 }
176 |  |
177 |  |
                 // otherwise, unwrap the list and check the primitive
178 | 1284 |
                 obj = list.get(0);
179 |  |
             }
180 |  |
181 |  |
             // now check for primitive types
182 |  |
             // otherwise a non-empty node-set is true
183 |  |
184 |  |
             // if it's a Boolean, let it decide
185 | 21468 |
             if ( obj instanceof Boolean )
186 |  |
             {
187 | 19956 |
                 return (Boolean) obj;
188 |  |
             }
189 |  |
             // if it's a Number, != 0 -> true
190 | 1512 |
             else if ( obj instanceof Number )
191 |  |
             {
192 | 222 |
                 double d = ((Number) obj).doubleValue();
193 | 222 |
                 if ( d == 0 || Double.isNaN(d) )
194 |  |
                 {
195 | 48 |
                     return Boolean.FALSE;
196 |  |
                 }
197 | 174 |
                 return Boolean.TRUE;
198 |  |
             }
199 |  |
             // if it's a String, "" -> false
200 | 1290 |
             else if ( obj instanceof String )
201 |  |
             {
202 | 24 |
                 return ( ((String)obj).length() > 0
203 |  |
                          ? Boolean.TRUE
204 |  |
                          : Boolean.FALSE );
205 |  |
             }
206 |  |
             else
207 |  |
             {
208 |  |
                 // assume it's a node so that this node-set is non-empty
209 |  |
                 // and so it's true
210 | 1266 |
                 return ( obj != null ) ? Boolean.TRUE : Boolean.FALSE;
211 |  |
             }
212 |  |
213 |  |
         }
214 |  |
     }