    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.ioc.internal.util.InternalUtils;
    020import 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 */
    028public 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}