001// Copyright 2004, 2005 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.hivemind.schema.rules;
016
017import org.apache.hivemind.HiveMind;
018import org.apache.hivemind.Location;
019import org.apache.hivemind.internal.Module;
020import org.apache.hivemind.schema.Translator;
021
022/**
023 * Used to translate a value into a reference to a HiveMind service within the registry.
024 * 
025 * @author Howard Lewis Ship
026 */
027public class ServiceTranslator implements Translator
028{
029    /**
030     * Returns null if the input is null or empty. Returns the service with the given name
031     * otherwise. Will log an error and return null if an exception is thrown. If the input value is
032     * not qualified, the contributing module's id is added as a prefix.
033     */
034    public Object translate(Module contributingModule, Class propertyType, String inputValue,
035            Location location)
036    {
037        if (HiveMind.isBlank(inputValue))
038            return null;
039
040        return contributingModule.getService(inputValue, Object.class);
041    }
042
043}