001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.core.util.objects.checker;
018
019import org.apache.wicket.Page;
020
021/**
022 * An implementation of {@link IObjectChecker} that returns a failure
023 * result when the checked object is a second {@link org.apache.wicket.Page} instance
024 * in the component tree. The first checked page instance is assumed to be the component
025 * tree root. Any other page instance checked by the same checker is a referenced page
026 * by a component in the tree.
027 *
028 * @since 6.17.0
029 */
030public class DifferentPageChecker extends AbstractObjectChecker
031{
032        private Page root;
033
034        @Override
035        public Result doCheck(Object obj)
036        {
037                Result result = Result.SUCCESS;
038
039                if (obj instanceof Page)
040                {
041                        if (root != null && root != obj)
042                        {
043                                result = new Result(Result.Status.FAILURE, "Trying to serialize a page which is not the component tree root!");
044                        }
045                        else
046                        {
047                                root = (Page) obj;
048                        }
049                }
050
051                return result;
052        }
053}