content: /**
   * Copyright 2014 55 Minutes (http://www.55minutes.com)
   *
   * 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 fiftyfive.wicket.shiro.markup;
  
  import fiftyfive.wicket.shiro.ShiroWicketPlugin;
  import org.apache.shiro.authz.annotation.RequiresUser;
  import org.apache.wicket.Page;
  import org.apache.wicket.markup.html.link.BookmarkablePageLink;
  import org.apache.wicket.protocol.http.RequestUtils;
  import org.apache.wicket.request.mapper.parameter.PageParameters;
  
  /**
   * A simple bookmarkable link to the {@link LogoutPage} that is hidden for users who aren't
   * logged in. Upon logout, the user will be sent to the home page or another page as specified
   * by the {@code LogoutLink} constructor.
   * 
   * @author Matt Brictson
   * @since 3.0
   */
  @RequiresUser
  public class LogoutLink extends BookmarkablePageLink
  {
      private final Class<? extends Page> destinationPage;
      private final PageParameters destinationParams;
      
      /**
       * Construct a logout link that will cause the user to be redirected to
       * the home page after the logout operation is performed.
       */
      public LogoutLink(String id)
      {
          this(id, null, null);
      }
      
      /**
       * Construct a logout link that will cause the user to be redirected to
       * the specified page after the logout operation is performed.
       */
      public LogoutLink(String id, Class<? extends Page> destination)
      {
          this(id, destination, null);
      }
      
      /**
       * Construct a logout link that will cause the user to be redirected to
       * the specified page and parameters after the logout operation is performed.
       */
      public LogoutLink(String id,
                        Class<? extends Page> destinationPage,
                        PageParameters destinationParams)
      {
          super(id, ShiroWicketPlugin.get().getLogoutPage());
          this.destinationPage = destinationPage;
          this.destinationParams = destinationParams;
      }
      
      /**
       * If a destination page was specified in the constructor, determine the absolute URI for
       * that page and add it to this link as the {@code "to"} parameter. This instructs the
       * {@link LogoutPage} to redirect to that URI upon logout.
       */
      @Override
      protected void onInitialize()
      {
          super.onInitialize();
  
          Class<? extends Page> dest = this.destinationPage;
          if(dest != null)
          {
              getPageParameters().set("to", RequestUtils.toAbsolutePath(
                  getRequest().getClientUrl().toString(),
                  urlFor(dest, this.destinationParams).toString()));
          }
      }
  }
  