    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005// http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5.services;
    014
    015import org.apache.tapestry5.http.Link;
    016import org.apache.tapestry5.http.services.Request;
    017import org.apache.tapestry5.services.linktransform.ComponentEventLinkTransformer;
    018import org.apache.tapestry5.services.linktransform.PageRenderLinkTransformer;
    019
    020/**
    021 * Responsible for creating {@link org.apache.tapestry5.http.Link}s for page render requests and for component event
    022 * requests, and for parsing incoming paths to identify requests that are component event or page render requests. This
    023 * centralizes some logic that was scattered about in Tapestry 5.0.
    024 *
    025 * @since 5.1.0.1
    026 */
    027public interface ComponentEventLinkEncoder
    028{
    029    /**
    030     * Creates a Link that encapsulates a page render request, including activation context <em>and {@link
    031     * org.apache.tapestry5.services.PersistentLocale} (if set)</em>.
    032     * Passes the resulting Link through the {@link PageRenderLinkTransformer} chain of command, returning
    033     * the result.
    034     *
    035     * @param parameters
    036     *            defining page to render and context
    037     * @return link for the page render
    038     */
    039    Link createPageRenderLink(PageRenderRequestParameters parameters);
    040
    041    /**
    042     * Creates a link that encapsulates a component event request, including <em>{@link
    043     * org.apache.tapestry5.services.PersistentLocale} (if set)</em>.
    044     *
    045     * Forms:
    046     * <ul>
    047     * <li>/context/pagename:eventname -- event on the page, no action context</li>
    048     * <li>/context/pagename:eventname/foo/bar -- event on the page with action context "foo", "bar"</li>
    049     * <li>/context/pagename.foo.bar -- event on component foo.bar within the page, default event, no action context</li>
    050     * <li>/context/pagename.foo.bar/baz.gnu -- event on component foo.bar within the page, default event, with action
    051     * context "baz", "gnu"</li>
    052     * <li>/context/pagename.bar.baz:eventname/foo/gnu -- event on component bar.baz within the page with action context
    053     * "foo" , "gnu"</li>
    054     * </ul>
    055     *
    056     * The persistent locale may be placed in between the context name and the page name, i.e., "/context/fr/SomePage".
    057     *
    058     * In many cases the context name is blank, so the path begins with a "/" and then the locale name or page name.
    059     *
    060     * The page name portion may itself consist of a series of folder names, i.e., "admin/user/create". The context
    061     * portion isn't the concern of this code, since {@link org.apache.tapestry5.http.services.Request#getPath()} will
    062     * already have stripped that off. We can act as if the context is always "/" (the path always starts with a slash).
    063     *
    064     * Passes the resulting Link through the {@link ComponentEventLinkTransformer} chain of command, returning the
    065     * result.
    066     *
    067     * @param parameters
    068     *            defining page, component, activation context and other details
    069     * @param forForm
    070     *            true if the event link will trigger a form submission
    071     * @return link for the component event
    072     */
    073    Link createComponentEventLink(ComponentEventRequestParameters parameters, boolean forForm);
    074
    075    /**
    076     * Checks the request, primarily the {@linkplain org.apache.tapestry5.http.services.Request#getPath() path}, to determine
    077     * the if the request is a component event request. As a side-effect (necessary for historical reasons), responsible
    078     * for setting the locale for the thread, including the {@link org.apache.tapestry5.services.PersistentLocale} ...
    079     * but only if the locale is a component event.
    080     *
    081     * @param request
    082     *            incoming request
    083     * @return component event request details, if a component event request
    084     */
    085    ComponentEventRequestParameters decodeComponentEventRequest(Request request);
    086
    087    /**
    088     * Checks the request, primarily the {@linkplain org.apache.tapestry5.http.services.Request#getPath() path}, to determine
    089     * the if the request is a page render request. As a side-effect (necessary for historical reasons), responsible for
    090     * setting the locale for the thread, including the {@link org.apache.tapestry5.services.PersistentLocale} ... but
    091     * only if the request is a page render.
    092     *
    093     * @param request
    094     *            incoming request
    095     * @return page render request details, if a page render request
    096     */
    097    PageRenderRequestParameters decodePageRenderRequest(Request request);
    098}