| // Copyright 2010 The Apache Software Foundation |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package org.apache.tapestry5; |
| |
| import java.io.Serializable; |
| |
| import org.apache.tapestry5.annotations.ImmutableSessionPersistedObject; |
| import org.apache.tapestry5.internal.InternalConstants; |
| import org.apache.tapestry5.ioc.internal.util.InternalUtils; |
| import org.apache.tapestry5.services.PageRenderLinkSource; |
| |
| /** |
| * A way of capturing the name of a page and the page activation context so that, at a future date, |
| * the page can be invoked with that data. This kind of callback is very useful when creating more |
| * complicated workflows, where access to a page is "interrupted" with some operation before |
| * returning (via a callback) to the original flow. |
| * <p> |
| * Since the callback is serializable, it can be stored in the session. |
| * |
| * @since 5.2.0 |
| */ |
| @ImmutableSessionPersistedObject |
| public class PageCallback implements Serializable |
| { |
| private static final long serialVersionUID = -8067619978636824702L; |
| |
| private String pageName; |
| |
| private String[] activationContext; |
| |
| public PageCallback(String pageName, String[] activationContext) |
| { |
| assert InternalUtils.isNonBlank(pageName); |
| this.pageName = pageName; |
| assert activationContext != null; |
| this.activationContext = activationContext; |
| } |
| |
| public PageCallback(String pageName, EventContext activationContext) |
| { |
| this(pageName, activationContext.toStrings()); |
| } |
| |
| public PageCallback(String pageName) |
| { |
| this(pageName, InternalConstants.EMPTY_STRING_ARRAY); |
| } |
| |
| public String getPageName() |
| { |
| return pageName; |
| } |
| |
| @Override |
| public String toString() |
| { |
| if (hasActivationContext()) |
| return String.format("PageCallback[%s %s]", pageName, activationContextDescription()); |
| |
| return String.format("PageCallback[%s]", pageName); |
| } |
| |
| /** Does the activation context have any values? Used, typically, inside an override of {@link #toString()}. */ |
| protected final boolean hasActivationContext() |
| { |
| return activationContext.length > 0; |
| } |
| |
| /** |
| * Returns the activation context as a string of value separated by slashes. Typically used inside |
| * an override of {@link #toString()}. |
| */ |
| protected final String activationContextDescription() |
| { |
| StringBuilder builder = new StringBuilder(); |
| |
| String sep = ""; |
| |
| for (String c : activationContext) |
| { |
| builder.append(sep); |
| builder.append(c); |
| |
| sep = "/"; |
| } |
| |
| return builder.toString(); |
| } |
| |
| /** |
| * Converts the callback (the page name and activation context) to a link; such a link may be |
| * returned from a event handler method to cause Tapestry to redirect to the page. Most of the |
| * details |
| * are encapsulated inside the {@link PageRenderLinkSource} service. |
| * |
| * @param linkSource |
| * used to generate the link |
| * @return link corresponding to this callback |
| */ |
| public Link toLink(PageRenderLinkSource linkSource) |
| { |
| return linkSource.createPageRenderLinkWithContext(pageName, (Object[]) activationContext); |
| } |
| } |