    001// Copyright 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.ioc.internal;
    016
    017import org.apache.tapestry5.commons.services.TypeCoercer;
    018
    019/**
    020 * A simplified version of {@link TypeCoercer} used to defer the instantiation of the actual TypeCoercer
    021 * service until necessary.
    022 *
    023 * @since 5.3
    024 */
    025public interface TypeCoercerProxy
    026{
    027    /**
    028     * Returns input cast to targetType if input is an instance of target type, otherwise delegates
    029     * to {@link TypeCoercer#coerce(Object, Class)}.
    030     *
    031     * @param <S>
    032     * @param <T>
    033     * @param input
    034     *            value to be coerced
    035     * @param targetType
    036     *            desired type of value
    037     * @return the value, coerced
    038     * @throws RuntimeException
    039     *             if the input can not be coerced
    040     */
    041    <S, T> T coerce(S input, Class<T> targetType);
    042
    043}