Coverage Report

Coverage Report - org.jaxen.function.BooleanFunction

Classes in this File

Line Coverage

Branch Coverage

Complexity

BooleanFunction

100%

19/19

100%

9/9

5.667

 /*
  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/BooleanFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
  * $Revision: 1.17 $
  * $Date: 2006/02/05 21:47:41 $
  *
  * ====================================================================
  *
  * Copyright 2000-2002 bob mcwhirter & James Strachan.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  * 
  *   * Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 
  *   * Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 
  *   * Neither the name of the Jaxen Project nor the names of its
  *     contributors may be used to endorse or promote products derived 
  *     from this software without specific prior written permission.
  * 
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * ====================================================================
  * This software consists of voluntary contributions made by many 
  * individuals on behalf of the Jaxen Project and was originally 
  * created by bob mcwhirter <bob@werken.com> and 
  * James Strachan <jstrachan@apache.org>.  For more information on the 
  * Jaxen Project, please see <http://www.jaxen.org/>.
  * 
  * $Id: BooleanFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
  */
 
 
 package org.jaxen.function;
 
 import java.util.List;
 
 import org.jaxen.Context;
 import org.jaxen.Function;
 import org.jaxen.FunctionCallException;
 import org.jaxen.Navigator;
 
 /**
  * <p>
  * <b>4.3</b> <code><i>boolean</i> boolean(<i>object</i>)</code>
  * </p>
  * 
  * <blockquote
  * src="http://www.w3.org/TR/xpath#section-Boolean-Functions">
  * <p>
  * The <b><a href="http://www.w3.org/TR/xpath#function-boolean" target="_top">boolean</a></b>
  * function converts its argument to a boolean as follows:
  * </p>
  * 
  * <ul>
  * 
  * <li>
  * <p>
  * a number is true if and only if it is neither positive or negative
  * zero nor NaN
  * </p>
  * </li>
  * 
  * <li>
  * <p>
  * a node-set is true if and only if it is non-empty
  * </p>
  * </li>
  * 
  * <li>
  * <p>
  * a string is true if and only if its length is non-zero
  * </p>
  * </li>
  * 
  * <li>
  * 
  * <p>
  * an object of a type other than the four basic types is converted to a
  * boolean in a way that is dependent on that type
  * </p></li></ul>
  * </blockquote>
  * 
  * @author bob mcwhirter (bob @ werken.com)
  * @see <a href="http://www.w3.org/TR/xpath#function-boolean">Section 4.3 of the XPath Specification</a>
  */
 public class BooleanFunction implements Function
 {
 
 
     /**
      * Create a new <code>BooleanFunction</code> object.
      */
     public BooleanFunction() {}
     
     /** Convert the argument to a <code>Boolean</code>
      *
      * @param context the context at the point in the
      *         expression when the function is called
      * @param args a list with exactly one item which will be converted to a 
      *     <code>Boolean</code>
      * 
      * @return the result of evaluating the function; 
      *     <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
      * 
      * @throws FunctionCallException if <code>args</code> has more or less than one item
      */
     public Object call(Context context,
                        List args) throws FunctionCallException
     {
         if ( args.size() == 1 )
         {
             return evaluate( args.get(0), context.getNavigator() );
         }
 
         throw new FunctionCallException("boolean() requires one argument");
     }
 
     /** 
      * <p>Convert the argument <code>obj</code> to a <code>Boolean</code> 
      * according to the following rules:</p>
      *
      * <ul>
      * <li>Lists are false if they're empty; true if they're not.</li>
      * <li>Booleans are false if they're false; true if they're true.</li>
      * <li>Strings are false if they're empty; true if they're not.</li>
      * <li>Numbers are false if they're 0 or NaN; true if they're not.</li>
      * <li>All other objects are true.</li>
      * </ul>
      * 
      * @param obj the object to convert to a boolean
      * @param nav ignored
      * 
      * @return <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
      */
     public static Boolean evaluate(Object obj, Navigator nav)
     {
         if ( obj instanceof List )
         {
             List list = (List) obj;
             
             // if it's an empty list, then we have a null node-set -> false            
             if (list.size() == 0)
             {
                 return Boolean.FALSE;
             }
      
             // otherwise, unwrap the list and check the primitive
             obj = list.get(0);
         }
         
         // now check for primitive types
         // otherwise a non-empty node-set is true
 
         // if it's a Boolean, let it decide
         if ( obj instanceof Boolean )
         {
             return (Boolean) obj;
         }
         // if it's a Number, != 0 -> true
         else if ( obj instanceof Number )
         {
             double d = ((Number) obj).doubleValue();
             if ( d == 0 || Double.isNaN(d) )
             {
                 return Boolean.FALSE;
             }
             return Boolean.TRUE;
         }
         // if it's a String, "" -> false
         else if ( obj instanceof String )
         {
             return ( ((String)obj).length() > 0
                      ? Boolean.TRUE
                      : Boolean.FALSE );
         }
         else 
         {
             // assume it's a node so that this node-set is non-empty 
             // and so it's true
             return ( obj != null ) ? Boolean.TRUE : Boolean.FALSE;
         }
 
     }
 }

1		/*
2		* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/BooleanFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
3		* $Revision: 1.17 $
4		* $Date: 2006/02/05 21:47:41 $
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: BooleanFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
46		*/
47
48
49		package org.jaxen.function;
50
51		import java.util.List;
52
53		import org.jaxen.Context;
54		import org.jaxen.Function;
55		import org.jaxen.FunctionCallException;
56		import org.jaxen.Navigator;
57
58		/**
59		* <p>
60		* <b>4.3</b> <code><i>boolean</i> boolean(<i>object</i>)</code>
61		* </p>
62		*
63		* <blockquote
64		* src="http://www.w3.org/TR/xpath#section-Boolean-Functions">
65		* <p>
66		* The <b><a href="http://www.w3.org/TR/xpath#function-boolean" target="_top">boolean</a></b>
67		* function converts its argument to a boolean as follows:
68		* </p>
69		*
70		* <ul>
71		*
72		* <li>
73		* <p>
74		* a number is true if and only if it is neither positive or negative
75		* zero nor NaN
76		* </p>
77		* </li>
78		*
79		* <li>
80		* <p>
81		* a node-set is true if and only if it is non-empty
82		* </p>
83		* </li>
84		*
85		* <li>
86		* <p>
87		* a string is true if and only if its length is non-zero
88		* </p>
89		* </li>
90		*
91		* <li>
92		*
93		* <p>
94		* an object of a type other than the four basic types is converted to a
95		* boolean in a way that is dependent on that type
96		* </p></li></ul>
97		* </blockquote>
98		*
99		* @author bob mcwhirter (bob @ werken.com)
100		* @see <a href="http://www.w3.org/TR/xpath#function-boolean">Section 4.3 of the XPath Specification</a>
101		*/
102		public class BooleanFunction implements Function
103		{
104
105
106		/**
107		* Create a new <code>BooleanFunction</code> object.
108		*/
109	106	public BooleanFunction() {}
110
111		/** Convert the argument to a <code>Boolean</code>
112		*
113		* @param context the context at the point in the
114		* expression when the function is called
115		* @param args a list with exactly one item which will be converted to a
116		* <code>Boolean</code>
117		*
118		* @return the result of evaluating the function;
119		* <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
120		*
121		* @throws FunctionCallException if <code>args</code> has more or less than one item
122		*/
123		public Object call(Context context,
124		List args) throws FunctionCallException
125		{
126	16	if ( args.size() == 1 )
127		{
128	12	return evaluate( args.get(0), context.getNavigator() );
129		}
130
131	4	throw new FunctionCallException("boolean() requires one argument");
132		}
133
134		/**
135		* <p>Convert the argument <code>obj</code> to a <code>Boolean</code>
136		* according to the following rules:</p>
137		*
138		* <ul>
139		* <li>Lists are false if they're empty; true if they're not.</li>
140		* <li>Booleans are false if they're false; true if they're true.</li>
141		* <li>Strings are false if they're empty; true if they're not.</li>
142		* <li>Numbers are false if they're 0 or NaN; true if they're not.</li>
143		* <li>All other objects are true.</li>
144		* </ul>
145		*
146		* @param obj the object to convert to a boolean
147		* @param nav ignored
148		*
149		* @return <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
150		*/
151		public static Boolean evaluate(Object obj, Navigator nav)
152		{
153	7218	if ( obj instanceof List )
154		{
155	434	List list = (List) obj;
156
157		// if it's an empty list, then we have a null node-set -> false
158	434	if (list.size() == 0)
159		{
160	6	return Boolean.FALSE;
161		}
162
163		// otherwise, unwrap the list and check the primitive
164	428	obj = list.get(0);
165		}
166
167		// now check for primitive types
168		// otherwise a non-empty node-set is true
169
170		// if it's a Boolean, let it decide
171	7212	if ( obj instanceof Boolean )
172		{
173	6692	return (Boolean) obj;
174		}
175		// if it's a Number, != 0 -> true
176	520	else if ( obj instanceof Number )
177		{
178	90	double d = ((Number) obj).doubleValue();
179	90	if ( d == 0 \|\| Double.isNaN(d) )
180		{
181	16	return Boolean.FALSE;
182		}
183	74	return Boolean.TRUE;
184		}
185		// if it's a String, "" -> false
186	430	else if ( obj instanceof String )
187		{
188	8	return ( ((String)obj).length() > 0
189		? Boolean.TRUE
190		: Boolean.FALSE );
191		}
192		else
193		{
194		// assume it's a node so that this node-set is non-empty
195		// and so it's true
196	422	return ( obj != null ) ? Boolean.TRUE : Boolean.FALSE;
197		}
198
199		}
200		}