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.ApplicationRuntimeException;
022    import org.apache.hivemind.util.Defense;
023    import org.apache.tapestry.IComponent;
024    import org.apache.tapestry.IDirectEvent;
025    import org.apache.tapestry.IPage;
026    import org.apache.tapestry.IRequestCycle;
027    import org.apache.tapestry.StaleSessionException;
028    import org.apache.tapestry.Tapestry;
029    import org.apache.tapestry.event.BrowserEvent;
030    import org.apache.tapestry.services.LinkFactory;
031    import org.apache.tapestry.services.ResponseRenderer;
032    import org.apache.tapestry.services.ServiceConstants;
033    import org.apache.tapestry.web.WebRequest;
034    import org.apache.tapestry.web.WebSession;
035    
036    /**
037     * Implementation of the direct event service, which encodes the page and component id in the service
038     * context, and passes application-defined parameters as well.
039     * 
040     * @author jkuhnert
041     * @since 4.1
042     */
043    
044    public class DirectEventService implements IEngineService
045    {   
046        /** @since 4.0 */
047        private ResponseRenderer _responseRenderer;
048    
049        /** @since 4.0 */
050        private LinkFactory _linkFactory;
051    
052        /** @since 4.0 */
053        private WebRequest _request;
054    
055        /** @since 4.0 */
056        private IRequestCycle _requestCycle;
057    
058        public ILink getLink(boolean post, Object parameter)
059        {
060            Defense.isAssignable(parameter, DirectEventServiceParameter.class, "parameter");
061    
062            DirectEventServiceParameter dsp = (DirectEventServiceParameter) parameter;
063    
064            IComponent component = dsp.getDirect();
065    
066            // New since 1.0.1, we use the component to determine
067            // the page, not the cycle. Through the use of tricky
068            // things such as Block/InsertBlock, it is possible
069            // that a component from a page different than
070            // the response page will render.
071            // In 1.0.6, we start to record *both* the render page
072            // and the component page (if different).
073    
074            IPage activePage = _requestCycle.getPage();
075            IPage componentPage = component.getPage();
076            
077            Map parameters = new HashMap();
078            
079            boolean stateful = _request.getSession(false) != null;
080            
081            parameters.put(ServiceConstants.PAGE, activePage.getPageName());
082            parameters.put(ServiceConstants.COMPONENT, component.getIdPath());
083            parameters.put(ServiceConstants.CONTAINER, componentPage == activePage ? null
084                    : componentPage.getPageName());
085            parameters.put(ServiceConstants.SESSION, stateful ? "T" : null);
086            if (dsp.getUpdateParts() != null && dsp.getUpdateParts().length > 0)
087                parameters.put(ServiceConstants.UPDATE_PARTS, dsp.getUpdateParts());
088            if (dsp.isJSON())
089                parameters.put("json", String.valueOf(dsp.isJSON()));
090            parameters.put(ServiceConstants.PARAMETER, dsp.getServiceParameters());
091            
092            return _linkFactory.constructLink(this, post, parameters, true);
093        }
094    
095        public void service(IRequestCycle cycle) throws IOException
096        {
097            String componentId = cycle.getParameter(ServiceConstants.COMPONENT);
098            String componentPageName = cycle.getParameter(ServiceConstants.CONTAINER);
099            String activePageName = cycle.getParameter(ServiceConstants.PAGE);
100            boolean activeSession = cycle.getParameter(ServiceConstants.SESSION) != null;
101            
102            IPage page = cycle.getPage(activePageName);
103    
104            cycle.activate(page);
105    
106            IPage componentPage = componentPageName == null ? page : cycle.getPage(componentPageName);
107    
108            IComponent component = componentPage.getNestedComponent(componentId);
109    
110            IDirectEvent direct = null;
111    
112            try
113            {
114                direct = (IDirectEvent) component;
115            }
116            catch (ClassCastException ex)
117            {
118                throw new ApplicationRuntimeException(EngineMessages.wrongComponentType(
119                        component,
120                        IDirectEvent.class), component, null, ex);
121            }
122    
123            // Check for a StaleSession only when the session was stateful when
124            // the link was created.
125    
126            if (activeSession && direct.isStateful())
127            {
128                WebSession session = _request.getSession(false);
129    
130                if (session == null || session.isNew())
131                    throw new StaleSessionException(EngineMessages.requestStateSession(direct),
132                            componentPage);
133            }
134            
135            Object[] parameters = _linkFactory.extractListenerParameters(cycle);
136            
137            triggerComponent(cycle, direct, parameters);
138            
139            // Render the response. This will be the active page
140            // unless the direct component (or its delegate) changes it.
141            
142            _responseRenderer.renderResponse(cycle);
143        }
144    
145        /** @since 4.0 */
146    
147        protected void triggerComponent(IRequestCycle cycle, IDirectEvent direct, Object[] parameters)
148        {
149            if (!BrowserEvent.hasBrowserEvent(cycle))
150                throw new ApplicationRuntimeException(EngineMessages.noBrowserEvent());
151            
152            BrowserEvent event = new BrowserEvent(cycle);
153            
154            Object[] parms = new Object[parameters.length + 1];
155            System.arraycopy(parameters, 0, parms, 0, parameters.length);
156            parms[parms.length - 1] = event;
157            
158            cycle.setListenerParameters(parms);
159            
160            direct.triggerEvent(cycle, event);
161        }
162    
163        public String getName()
164        {
165            return Tapestry.DIRECT_EVENT_SERVICE;
166        }
167    
168        /** @since 4.0 */
169        public void setResponseRenderer(ResponseRenderer responseRenderer)
170        {
171            _responseRenderer = responseRenderer;
172        }
173    
174        /** @since 4.0 */
175        public void setLinkFactory(LinkFactory linkFactory)
176        {
177            _linkFactory = linkFactory;
178        }
179    
180        /** @since 4.0 */
181        public void setRequest(WebRequest request)
182        {
183            _request = request;
184        }
185    
186        /** @since 4.0 */
187        public void setRequestCycle(IRequestCycle requestCycle)
188        {
189            _requestCycle = requestCycle;
190        }
191    }