001// Copyright 2010, 2011 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;
016
017import org.apache.tapestry5.ComponentResources;
018
019/**
020 * An object used to provide a value of a specific type to a component (represented by an
021 * instance of {@link ComponentResources}). The provider will create and return the value
022 * (some providers may be smart enough to cache a value, but should be implemented in
023 * a thread-safe manner). Often the provider is an inner class of a {@link ComponentClassTransformWorker}.
024 * 
025 * @param <T>
026 *            type of object provided
027 * @since 5.2.0
028 * @deprecated Deprecated in 5.3, using Plastic equivalents
029 * @see org.apache.tapestry5.plastic.PlasticField
030 * @see org.apache.tapestry5.plastic.ComputedValue
031 */
032@SuppressWarnings("deprecation")
033public interface ComponentValueProvider<T>
034{
035    /**
036     * Provide the object for the indicated component.
037     * 
038     * @param resources
039     *            Identifies the component
040     * @return the object
041     */
042    T get(ComponentResources resources);
043}