    001// Copyright 2009, 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;
    016
    017import org.apache.tapestry5.Link;
    018import org.apache.tapestry5.services.linktransform.ComponentEventLinkTransformer;
    019import org.apache.tapestry5.services.linktransform.PageRenderLinkTransformer;
    020
    021/**
    022 * Responsible for creating {@link org.apache.tapestry5.Link}s for page render requests and for component event
    023 * requests, and for parsing incoming paths to identify requests that are component event or page render requests. This
    024 * centralizes some logic that was scattered about in Tapestry 5.0.
    025 *
    026 * @since 5.1.0.1
    027 */
    028public interface ComponentEventLinkEncoder
    029{
    030    /**
    031     * Creates a Link that encapsulates a page render request, including activation context <em>and {@link
    032     * org.apache.tapestry5.services.PersistentLocale} (if set)</em>.
    033     * Passes the resulting Link through the {@link PageRenderLinkTransformer} chain of command, returning
    034     * the result.
    035     *
    036     * @param parameters
    037     *            defining page to render and context
    038     * @return link for the page render
    039     */
    040    Link createPageRenderLink(PageRenderRequestParameters parameters);
    041
    042    /**
    043     * Creates a link that encapsulates a component event request, including <em>{@link
    044     * org.apache.tapestry5.services.PersistentLocale} (if set)</em>.
    045     * <p>
    046     * Forms:
    047     * <ul>
    048     * <li>/context/pagename:eventname -- event on the page, no action context</li>
    049     * <li>/context/pagename:eventname/foo/bar -- event on the page with action context "foo", "bar"</li>
    050     * <li>/context/pagename.foo.bar -- event on component foo.bar within the page, default event, no action context</li>
    051     * <li>/context/pagename.foo.bar/baz.gnu -- event on component foo.bar within the page, default event, with action
    052     * context "baz", "gnu"</li>
    053     * <li>/context/pagename.bar.baz:eventname/foo/gnu -- event on component bar.baz within the page with action context
    054     * "foo" , "gnu"</li>
    055     * </ul>
    056     * <p/>
    057     * The persistent locale may be placed in between the context name and the page name, i.e., "/context/fr/SomePage".
    058     * <p/>
    059     * In many cases the context name is blank, so the path begins with a "/" and then the locale name or page name.
    060     * <p/>
    061     * The page name portion may itself consist of a series of folder names, i.e., "admin/user/create". The context
    062     * portion isn't the concern of this code, since {@link org.apache.tapestry5.services.Request#getPath()} will
    063     * already have stripped that off. We can act as if the context is always "/" (the path always starts with a slash).
    064     * <p/>
    065     * Passes the resulting Link through the {@link ComponentEventLinkTransformer} chain of command, returning the
    066     * result.
    067     *
    068     * @param parameters
    069     *            defining page, component, activation context and other details
    070     * @param forForm
    071     *            true if the event link will trigger a form submission
    072     * @return link for the component event
    073     */
    074    Link createComponentEventLink(ComponentEventRequestParameters parameters, boolean forForm);
    075
    076    /**
    077     * Checks the request, primarily the {@linkplain org.apache.tapestry5.services.Request#getPath() path}, to determine
    078     * the if the request is a component event request. As a side-effect (necessary for historical reasons), responsible
    079     * for setting the locale for the thread, including the {@link org.apache.tapestry5.services.PersistentLocale} ...
    080     * but only if the locale is a component event.
    081     *
    082     * @param request
    083     *            incoming request
    084     * @return component event request details, if a component event request
    085     */
    086    ComponentEventRequestParameters decodeComponentEventRequest(Request request);
    087
    088    /**
    089     * Checks the request, primarily the {@linkplain org.apache.tapestry5.services.Request#getPath() path}, to determine
    090     * the if the request is a page render request. As a side-effect (necessary for historical reasons), responsible for
    091     * setting the locale for the thread, including the {@link org.apache.tapestry5.services.PersistentLocale} ... but
    092     * only if the request is a page render.
    093     *
    094     * @param request
    095     *            incoming request
    096     * @return page render request details, if a page render request
    097     */
    098    PageRenderRequestParameters decodePageRenderRequest(Request request);
    099}