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.request.mapper; 018 019import org.apache.wicket.request.IRequestMapper; 020import org.apache.wicket.request.Url; 021import org.apache.wicket.request.mapper.info.PageComponentInfo; 022import org.apache.wicket.util.lang.Args; 023import org.apache.wicket.util.string.Strings; 024 025/** 026 * Utility class that performs common functions used by {@link IRequestMapper}s. 027 */ 028public class MapperUtils 029{ 030 private MapperUtils() 031 { 032 } 033 034 /** 035 * Attempts to parse a {@link Url.QueryParameter} which may hold {@link PageComponentInfo}. 036 * 037 * @param parameter 038 * The {@link Url.QueryParameter} to parse. 039 * 040 * @return The parsed {@link PageComponentInfo}, or {@code null} if the parameter could not be parsed. 041 */ 042 public static PageComponentInfo parsePageComponentInfoParameter(final Url.QueryParameter parameter) 043 { 044 Args.notNull(parameter, "parameter"); 045 046 if (Strings.isEmpty(parameter.getName()) == false && Strings.isEmpty(parameter.getValue()) == true) 047 { 048 return PageComponentInfo.parse(parameter.getName()); 049 } 050 051 return null; 052 } 053 054 /** 055 * Extracts the {@link PageComponentInfo} from the URL. The {@link PageComponentInfo} is encoded 056 * as the very first query parameter and the parameter consists of name only (no value). 057 * 058 * @param url 059 * 060 * @return PageComponentInfo instance if one was encoded in URL, <code>null</code> otherwise. 061 */ 062 public static PageComponentInfo getPageComponentInfo(final Url url) 063 { 064 Args.notNull(url, "url"); 065 066 for (Url.QueryParameter queryParameter : url.getQueryParameters()) 067 { 068 PageComponentInfo pageComponentInfo = parsePageComponentInfoParameter(queryParameter); 069 070 if (pageComponentInfo != null) 071 { 072 return pageComponentInfo; 073 } 074 } 075 076 return null; 077 } 078}