    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
    015    package org.apache.tapestry5.ioc.internal;
    016
    017    import org.apache.tapestry5.ioc.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     */
    025    public 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    }