001 // Copyright 2011 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.tapestry5.corelib.mixins;
016
017 import org.apache.tapestry5.BindingConstants;
018 import org.apache.tapestry5.ComponentResources;
019 import org.apache.tapestry5.EventConstants;
020 import org.apache.tapestry5.EventContext;
021 import org.apache.tapestry5.Link;
022 import org.apache.tapestry5.annotations.AfterRender;
023 import org.apache.tapestry5.annotations.Import;
024 import org.apache.tapestry5.annotations.InjectContainer;
025 import org.apache.tapestry5.annotations.Parameter;
026 import org.apache.tapestry5.corelib.components.Zone;
027 import org.apache.tapestry5.internal.util.CaptureResultCallback;
028 import org.apache.tapestry5.ioc.annotations.Inject;
029 import org.apache.tapestry5.json.JSONObject;
030 import org.apache.tapestry5.services.javascript.InitializationPriority;
031 import org.apache.tapestry5.services.javascript.JavaScriptSupport;
032
033 /**
034 * <p>
035 * This mixin periodically refreshs a @{link org.apache.tapestry5.corelib.components.Zone zone}
036 * by triggering an event on the server using ajax requests.
037 * </p>
038 *
039 * <b>Note: </b> This mixin is only meant for a @{link org.apache.tapestry5.corelib.components.Zone zone}
040 * @tapestrydoc
041 */
042 @Import(library = "zone-refresh.js")
043 public class ZoneRefresh
044 {
045 /**
046 * Period between two consecutive refreshes (in seconds)
047 */
048 @Parameter(required = true, defaultPrefix = BindingConstants.LITERAL)
049 private int period;
050
051 /**
052 * Context passed to the event
053 */
054 @Parameter
055 private Object[] context;
056
057 @InjectContainer
058 private Zone zone;
059
060 @Inject
061 private JavaScriptSupport javaScriptSupport;
062
063 @Inject
064 private ComponentResources resources;
065
066 public ZoneRefresh()
067 {
068 }
069
070 //For testing purpose
071 ZoneRefresh(Object [] context, ComponentResources resources, JavaScriptSupport javaScriptSupport, Zone zone)
072 {
073 this.context = context;
074 this.resources = resources;
075 this.javaScriptSupport = javaScriptSupport;
076 this.zone = zone;
077 }
078
079 @AfterRender
080 void addJavaScript()
081 {
082 JSONObject params = new JSONObject();
083
084 params.put("period", period);
085 params.put("id", zone.getClientId());
086 params.put("URL", createEventLink());
087
088 javaScriptSupport.addInitializerCall(InitializationPriority.LATE, "zoneRefresh", params);
089 }
090
091 private Object createEventLink()
092 {
093 Link link = resources.createEventLink("zoneRefresh", context);
094 return link.toAbsoluteURI();
095 }
096
097 Object onZoneRefresh(EventContext eventContext)
098 {
099 CaptureResultCallback<Object> callback = new CaptureResultCallback<Object>();
100 resources.triggerContextEvent(EventConstants.REFRESH, eventContext, callback);
101
102 if(callback.getResult() != null){
103 return callback.getResult();
104 }
105
106 return zone.getBody();
107 }
108
109 }