001    // Copyright 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.form;
016    
017    import java.text.MessageFormat;
018    import java.util.Locale;
019    
020    import org.apache.hivemind.util.Defense;
021    import org.apache.tapestry.valid.ValidationStrings;
022    
023    /**
024     * Wrapper around
025     * {@link org.apache.tapestry.valid.ValidationStrings#getMessagePattern(String, Locale)} and
026     * {@link java.text.MessageFormat#format(java.lang.String, java.lang.Object[])}.
027     * 
028     * @author Howard Lewis Ship
029     * @since 4.0
030     */
031    public class ValidationMessagesImpl implements ValidationMessages
032    {
033        private final IFormComponent _field;
034    
035        private final Locale _locale;
036    
037        public ValidationMessagesImpl(IFormComponent field, Locale locale)
038        {
039            Defense.notNull(field, "field");
040            Defense.notNull(locale, "locale");
041    
042            _field = field;
043            _locale = locale;
044        }
045    
046        public String formatValidationMessage(String messageOverride, String messageKey,
047                Object[] arguments)
048        {
049            String message = extractLocalizedMessage(messageOverride, messageKey);
050    
051            return MessageFormat.format(message, arguments);
052        }
053    
054        private String extractLocalizedMessage(String messageOverride, String messageKey)
055        {
056            if (messageOverride == null)
057                return ValidationStrings.getMessagePattern(messageKey, _locale);
058    
059            if (messageOverride.startsWith("%"))
060            {
061                String key = messageOverride.substring(1);
062    
063                return _field.getContainer().getMessages().getMessage(key);
064            }
065    
066            // Otherwise, a literal string
067    
068            return messageOverride;
069        }
070    
071        public Locale getLocale()
072        {
073            return _locale;
074        }
075    
076    }