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    
015    package org.apache.tapestry5.services;
016    
017    import org.apache.tapestry5.Link;
018    import org.apache.tapestry5.services.linktransform.ComponentEventLinkTransformer;
019    import 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     */
028    public 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    }