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 org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
018import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
019
020/**
021 * Service that makes it easy to identify a class annotation and use its presence, or the value of an attribute,
022 * to set a meta-data key. The configuration map class annotation types to corresponding extractors who will be invoked
023 * when the annotation is present. Most commonly, a {@link FixedExtractor} is used to set a fixed value to a fixed key,
024 * triggered by the presence of the corresponding annotation.
025 *
026 * @since 5.2.0
027 */
028@UsesMappedConfiguration(key = Class.class, value = MetaDataExtractor.class)
029public interface MetaWorker
030{
031    /**
032     * Returns the worker that performs transformations (in 5.2, MetaWorker implemented ComponentClassTransformWorker).
033     *
034     * @return worker that implements the meta data analysis
035     */
036    ComponentClassTransformWorker2 getWorker();
037}