pre-wicket.1.2.5/wicket-examples/src/main/java/wicket/examples/compref/BookmarkablePage.java

/*
 * $Id$ $Revision$ $Date$
 * 
 * ==================================================================== 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 wicket.examples.compref;

import wicket.PageParameters;
import wicket.markup.html.WebPage;
import wicket.markup.html.basic.Label;
import wicket.markup.html.link.BookmarkablePageLink;

/**
 * Example page that cannot be bookmarked. A page is bookmarkable when it has a
 * public default constructor and/or a public constructor with a
 * {@link wicket.PageParameters} argument.
 * 
 * @author Eelco Hillenius
 */
public class BookmarkablePage extends WebPage
{
	/**
	 * Constructor.
	 */
	public BookmarkablePage()
	{
		this(null);
		// note: its here for style actually. When you have both a default
		// constructor,
		// and a constructor with a PageParameters argument, the latter is
		// allways called
		// with a non-null argument
	}

	/**
	 * Construct.
	 * 
	 * @param pageParameters
	 */
	public BookmarkablePage(PageParameters pageParameters)
	{
		// get the message from the passed 'message' parameter or fall back to
		// the default
		// when no parameters were passed.

		String message;
		// note: the null check is here as a matter of defensive programming.
		// Actually, as this
		// constructor is allways called instead of the default constructor, and
		// pageParameters
		// never null, the check is not nescesarry. On the other hand... would
		// you ever trust
		// any API enough to just not check it at all?
		if (pageParameters == null || pageParameters.getString("message") == null)
		{
			message = "This is the default message";
		}
		else
		{
			message = pageParameters.getString("message");
		}

		// Add a label to display the message
		add(new Label("messageLabel", message));

		// Add a link back. We did not hold any important instance data in
		// BookMarkabelPageLinkPage,
		// so navigating to a new instance is just fine
		add(new BookmarkablePageLink("navigateBackLink", BookmarkablePageLinkPage.class));
	}
}