    001// Copyright 2010 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.linktransform;
    016
    017import org.apache.tapestry5.Link;
    018import org.apache.tapestry5.internal.services.ComponentEventDispatcher;
    019import org.apache.tapestry5.ioc.annotations.UsesOrderedConfiguration;
    020import org.apache.tapestry5.services.ComponentEventRequestParameters;
    021import org.apache.tapestry5.services.LocalizationSetter;
    022import org.apache.tapestry5.services.Request;
    023
    024/**
    025 * Allows for selective replacement of the default {@link Link} used to represent a component event request.
    026 * This is a service, but also the contribution to the service, as a chain of command.
    027 * <p>
    028 * This transformer follows the same pattern as {@link PageRenderLinkTransformer}.
    029 *
    030 * @since 5.2.0
    031 */
    032@UsesOrderedConfiguration(ComponentEventLinkTransformer.class)
    033public interface ComponentEventLinkTransformer
    034{
    035    /**
    036     * Allows the default Link created for the component event request to be replaced.
    037     *
    038     * @param defaultLink
    039     *            the default Link generated for a component event request
    040     * @param parameters
    041     *            used to create the default Link
    042     * @return a replacement Link, or null
    043     */
    044    Link transformComponentEventLink(Link defaultLink, ComponentEventRequestParameters parameters);
    045
    046    /**
    047     * Attempts to decode the page render request, to perform the opposite action for
    048     * {@link #transformComponentEventLink(Link, ComponentEventRequestParameters)}. The transformer
    049     * is also responsible for identifying the locale in the request (as part of the path, or as a
    050     * query parameter or cookie) and setting the locale for the request.
    051     * <p>
    052     * This method will be invoked from the {@link ComponentEventDispatcher} and a non-null value returned from this
    053     * method will prevent the default
    054     * {@link org.apache.tapestry5.services.ComponentEventLinkEncoder#decodeComponentEventRequest(Request)} method
    055     * from being invoked.
    056     *
    057     * @return decoded parameters, or null to proceed normally
    058     * @see LocalizationSetter#setLocaleFromLocaleName(String)
    059     */
    060    ComponentEventRequestParameters decodeComponentEventRequest(Request request);
    061}