001// Copyright 2006, 2008, 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;
016
017/**
018 * Object passed into a service contributor method that allows the method provide contributed values to the service's
019 * configuration.
020 * <p/>
021 * A service can <em>collect</em> contributions in three different ways:
022 * <ul>
023 * <li>As an un-ordered collection of values</li>
024 * <li>As an ordered list of values (where each value has a unique id, pre-requisites and post-requisites)</li>
025 * <li>As a map of keys and values
026 * </ul>
027 * <p/>
028 * The service defines the <em>type</em> of contribution, in terms of a base class or service interface. Contributions
029 * must be compatible with the type.
030 */
031public interface MappedConfiguration<K, V>
032{
033
034    /**
035     * Adds a keyed object to the service's contribution.
036     * 
037     * @param key
038     *            unique id for the value
039     * @param value
040     *            to contribute
041     * @throws IllegalArgumentException
042     *             if key is not unique
043     */
044    void add(K key, V value);
045
046    /**
047     * Overrides an existing contribution by its key.
048     * 
049     * @param key
050     *            unique id of value to override
051     * @param value
052     *            new value, or null to remove the key entirely
053     * @since 5.1.0.0
054     */
055    void override(K key, V value);
056
057    /**
058     * Adds a keyed object as an instantiated instance (with dependencies injected) of a class. When the value
059     * type is an interface and the class to be contributed is a local file,
060     * then a reloadable proxy for the value class will be created and contributed.
061     * 
062     * @param key
063     *            unique id for the value
064     * @param clazz
065     *            class to instantiate and contribute
066     * @since 5.1.0.0
067     */
068    void addInstance(K key, Class<? extends V> clazz);
069
070    /**
071     * Overrides an existing contribution with a new instance. When the value
072     * type is an interface and the class to be contributed is a local file,
073     * then a reloadable proxy for the value class will be created and contributed.
074     * 
075     * @param key
076     *            unique id of value to override
077     * @param clazz
078     *            class to instantiate as override
079     */
080    void overrideInstance(K key, Class<? extends V> clazz);
081}