001// Copyright 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.tapestry.services.impl;
016
017import org.apache.hivemind.Locatable;
018
019/**
020 * Interface for an object that can provide a second, target object. This encapsulates the process
021 * of obtaining the target object (which is presumably expensive) so that the operation can be
022 * deferred or even avoided.
023 * 
024 * @author Howard M. Lewis Ship
025 * @since 4.0
026 * @see org.apache.tapestry.services.impl.DeferredObjectTranslator
027 */
028public interface DeferredObject extends Locatable
029{
030    /**
031     * Returns the target object. The caller is expected to cache the result, if appropriate.
032     */
033    public Object getObject();
034
035}