    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
    015package org.apache.tapestry5.services.meta;
    016
    017import java.lang.annotation.Annotation;
    018
    019import org.apache.tapestry5.model.ComponentModel;
    020import org.apache.tapestry5.model.MutableComponentModel;
    021import 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 */
    031public 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}