    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.model.ComponentModel;
    020    import org.apache.tapestry5.model.MutableComponentModel;
    021    import org.apache.tapestry5.services.MetaDataLocator;
    022
    023    /**
    024     * Used to extract a {@linkplain ComponentModel#getMeta(String) meta data value} from a component annotation. Instances
    025     * of this interface are contributed into the MetaWorker service.
    026     *
    027     * @since 5.2.0
    028     * @see MetaWorker
    029     * @see MetaDataLocator
    030     */
    031    public interface MetaDataExtractor<T extends Annotation>
    032    {
    033        /**
    034         * Invoked on the extractor to extract the appropriate value for the annotation and
    035         * {@linkplain MutableComponentModel#setMeta(String, String) set the meta data on the model}.
    036         *
    037         * @param model
    038         *            on which to set meta data
    039         * @param annotation
    040         *            class annotation, from whose attributes specific data may be extracted
    041         */
    042        void extractMetaData(MutableComponentModel model, T annotation);
    043    }