001    // Copyright 2007 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.tapestry5.internal.beaneditor;
016    
017    import org.apache.tapestry5.services.ValidationConstraintGenerator;
018    import org.apache.tapestry5.services.Environment;
019    import org.apache.tapestry5.services.PropertyEditContext;
020    import org.apache.tapestry5.ioc.AnnotationProvider;
021    import org.apache.tapestry5.ioc.Messages;
022    import org.apache.tapestry5.ioc.internal.util.InternalUtils;
023    
024    import java.util.List;
025    import java.util.Arrays;
026    import java.util.regex.Pattern;
027    
028    /**
029     * Generates constraints from the containing component's property file.
030     * Looks for a key in the form: propertyId-validate. 
031     *
032     */
033    public class MessagesConstraintGenerator implements ValidationConstraintGenerator
034    {
035    
036        private final Environment environment;
037        private final String format="%s-validate";
038        private final Pattern splitPattern;
039    
040        public MessagesConstraintGenerator(final Environment environment) {
041            this.environment = environment;
042            splitPattern = Pattern.compile(ValidateAnnotationConstraintGenerator.VALIDATOR_PATTERN);
043        }
044    
045        public List<String> buildConstraints(Class propertyType, AnnotationProvider annotationProvider)
046        {
047            EnvironmentMessages environmentMessages = environment.peek(EnvironmentMessages.class);
048            if (environmentMessages == null) {
049                return null;
050            }
051    
052            String key = String.format(format,environmentMessages.getOverrideId());
053            Messages m = environmentMessages.getMessages();
054            if (!m.contains(key))
055            {
056                return null;
057            }
058    
059            String result = m.get(key);
060            if (InternalUtils.isBlank(result))
061            {
062                return null;
063            }
064            return Arrays.asList(splitPattern.split(result));
065        }
066    }