001 // Copyright 2004, 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.tapestry.engine; 016 017 import java.io.IOException; 018 import java.util.HashMap; 019 import java.util.Map; 020 021 import org.apache.hivemind.util.Defense; 022 import org.apache.tapestry.IRequestCycle; 023 import org.apache.tapestry.Tapestry; 024 import org.apache.tapestry.services.LinkFactory; 025 import org.apache.tapestry.services.ResponseRenderer; 026 import org.apache.tapestry.services.ServiceConstants; 027 028 /** 029 * Basic server for creating a link to another page in the application. 030 * 031 * @author Howard Lewis Ship 032 * @since 1.0.9 033 */ 034 035 public class PageService implements IEngineService 036 { 037 /** @since 4.0 */ 038 private ResponseRenderer _responseRenderer; 039 040 /** @since 4.0 */ 041 private LinkFactory _linkFactory; 042 043 public ILink getLink(IRequestCycle cycle, boolean post, Object parameter) 044 { 045 Defense.isAssignable(parameter, String.class, "parameter"); 046 047 Map parameters = new HashMap(); 048 049 parameters.put(ServiceConstants.SERVICE, getName()); 050 parameters.put(ServiceConstants.PAGE, parameter); 051 052 return _linkFactory.constructLink(cycle, post, parameters, true); 053 054 } 055 056 public void service(IRequestCycle cycle) throws IOException 057 { 058 String pageName = cycle.getParameter(ServiceConstants.PAGE); 059 060 // At one time, the page service required a session, but that is no longer necessary. 061 // Users can now bookmark pages within a Tapestry application. Pages 062 // can implement validate() and throw a PageRedirectException if they don't 063 // want to be accessed this way. For example, most applications have a concept 064 // of a "login" and have a few pages that don't require the user to be logged in, 065 // and other pages that do. The protected pages should redirect to a login page. 066 067 cycle.activate(pageName); 068 069 _responseRenderer.renderResponse(cycle); 070 } 071 072 public String getName() 073 { 074 return Tapestry.PAGE_SERVICE; 075 } 076 077 /** @since 4.0 */ 078 public void setResponseRenderer(ResponseRenderer responseRenderer) 079 { 080 _responseRenderer = responseRenderer; 081 } 082 083 /** @since 4.0 */ 084 public void setLinkFactory(LinkFactory linkFactory) 085 { 086 _linkFactory = linkFactory; 087 } 088 }