    001    // Copyright 2008, 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.services;
    016
    017    /**
    018     * Used to convert values used in event contexts to client string representations and back.
    019     *
    020     * @see org.apache.tapestry5.ValueEncoder
    021     * @see org.apache.tapestry5.ioc.services.TypeCoercer
    022     */
    023    public interface ContextValueEncoder
    024    {
    025        /**
    026         * Converts a context value into a client-side string (that will ultimately be encoded into a URL).
    027         *
    028         * @param value to convert (may not be null)
    029         * @return string representation of the value
    030         * @see org.apache.tapestry5.ValueEncoder#toClient(Object)
    031         */
    032        String toClient(Object value);
    033
    034        /**
    035         * Converts a client value back into a server-side object.
    036         *
    037         * @param requiredType required type to convert the string to
    038         * @param clientValue  value obtained from context passed from client
    039         * @return the client value converted or coerced into a server value
    040         * @see org.apache.tapestry5.ValueEncoder#toValue(String)
    041         */
    042        <T> T toValue(Class<T> requiredType, String clientValue);
    043    }