001// Copyright 2009, 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.ioc.services;
016
017import org.apache.tapestry5.ioc.ObjectProvider;
018import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
019
020/**
021 * Used to override built in services. Simply contribute a mapping from a type to an instance of that type. Anywhere
022 * that exact type is injected, without specifying markers or other annotations, the contributed instance will be
023 * injected, even if there is already a service that implements the interface.
024 * <p>
025 * In fact, this is <em>not</em> limited to overriding services; any object that can be injected based solely on type
026 * can be contributed.
027 * 
028 * @since 5.1.0.0
029 */
030@UsesMappedConfiguration(key = Class.class, value = Object.class)
031public interface ServiceOverride
032{
033    /**
034     * Returns a provider based on the configuration; this is wired into the
035     * {@link org.apache.tapestry5.ioc.services.MasterObjectProvider}'s configuration.
036     */
037    ObjectProvider getServiceOverrideProvider();
038}