    001    // Copyright 2010 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.services.meta;
    016
    017    import java.lang.annotation.Annotation;
    018
    019    import org.apache.tapestry5.ioc.internal.util.InternalUtils;
    020    import org.apache.tapestry5.model.MutableComponentModel;
    021
    022    /**
    023     * Implementation of {@link MetaDataExtractor} that is used to set a fixed
    024     * value for a fixed meta-data key, when a given annotation is present.
    025     *
    026     * @since 5.2.0
    027     */
    028    public class FixedExtractor<T extends Annotation> implements MetaDataExtractor<T>
    029    {
    030        private final String key;
    031
    032        private final String value;
    033
    034        /** Defaults the value to "true". */
    035        public FixedExtractor(String key)
    036        {
    037            this(key, "true");
    038        }
    039
    040        public FixedExtractor(String key, String value)
    041        {
    042            assert InternalUtils.isNonBlank(key);
    043            this.key = key;
    044            assert InternalUtils.isNonBlank(value);
    045            this.value = value;
    046        }
    047
    048        public void extractMetaData(MutableComponentModel model, T annotation)
    049        {
    050            model.setMeta(key, value);
    051        }
    052
    053    }