    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
    015package 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.commons.services.TypeCoercer
    022 */
    023public 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}