001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.coerce;
016    
017    import org.apache.hivemind.HiveMind;
018    
019    /**
020     * Converts a String to a Boolean. Strings that do contain non-whitespace are considered true. As a
021     * special case, the string "false" evaluates to false (this allow boolean component parameters to
022     * be bound to "false" instead of "ognl:false" and still operate as expected).
023     * 
024     * @author Howard M. Lewis Ship
025     * @since 4.0
026     */
027    public final class StringToBooleanConverter implements TypeConverter
028    {
029    
030        public Object convertValue(Object value)
031        {
032            String s = (String) value;
033    
034            boolean b = HiveMind.isNonBlank(s) && !s.equals("false");
035    
036            // JDK 1.4 has a Boolean.valueOf(), but we're trying for 1.3 compatibility
037    
038            return b ? Boolean.TRUE : Boolean.FALSE;
039        }
040    
041    }