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
015package org.apache.tapestry.coerce;
016
017import 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 */
027public 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}