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Java > Open Source Codes > org > apache > jetspeed > modules > parameters > VelocityParameterPresentationStyle


1 /*
2  * Copyright 2000-2001,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.jetspeed.modules.parameters;
18
19 // Turbine support
20 import org.apache.turbine.util.RunData;
21 import org.apache.turbine.services.velocity.TurbineVelocity;
22 import org.apache.turbine.services.localization.LocalizationTool;
23 // Java stuff
24 import java.util.Map JavaDoc;
25
26 // jetspeed stuff
27 import org.apache.jetspeed.services.TemplateLocator;
28 import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
29 import org.apache.jetspeed.services.logging.JetspeedLogger;
30 import org.apache.jetspeed.util.template.BaseJetspeedLink;
31
32 // Velocity Stuff
33 import org.apache.velocity.context.Context;
34
35 /**
36  * Generic Velocity-based presentation style. The following default objects are put in the context:
37  * <UL>
38  * <LI>data - rundata object</LI>
39  * <LI>name - name of the parameter</LI>
40  * <LI>value - current value of the parameter</LI>
41  * <LI>parms - map of additional style parameters</LI>
42  * </UL>
43  *
44  * <P>Supporting Velocity templates should be placed in ${velocity-templates-root}/parameters folder.</p>
45  *
46  * <P>It may be used directly with "template" as the only required parameter. This is useful when the
47  * no additional objects are needed by the template.</P>
48  *
49  * <P>If additional objects need to be put in the context, a new class extending VelocityParameterPresentationStyle
50  * should be created. Override buildContext to place custom objects in the Velocity context.</P>
51  *
52  * <P>If "template" parameter is not specified, it is assumed that the template name is "classname.vm".</P>
53  *
54  * @author <a HREF="mailto:morciuch@apache.org">Mark Orciuch</a>
55  * @version $Id: VelocityParameterPresentationStyle.java,v 1.6 2004/02/23 03:01:20 jford Exp $
56  */
57
58 public class VelocityParameterPresentationStyle extends ParameterPresentationStyle
59 {
60
61     /**
62      * Static initialization of the logger for this class
63      */
64     private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(VelocityParameterPresentationStyle.class.getName());
65     
66     /**
67      * Returns presentation control
68      *
69      * @param data - rundata object
70      * @param name - parameter name
71      * @param value - current parameter value
72      * @param parms - additional style parameters
73      * @return string
74      */
75     public String JavaDoc getContent(RunData data, String JavaDoc name, String JavaDoc value, Map JavaDoc parms)
76     {
77         String JavaDoc result = null;
78
79         // create a blank context
80 Context context = TurbineVelocity.getContext();
81
82         // Put basics in the context
83 context.put("data", data);
84         context.put("name", name);
85         context.put("value", value);
86         context.put("parms", parms);
87         context.put("events", this.getJavascriptEvents());
88         LocalizationTool lt = new LocalizationTool();
89         lt.init(data);
90         context.put("l10n", lt);
91         context.put("jslink", new BaseJetspeedLink(data));
92
93         try
94         {
95             // Add custom objects to the context
96 this.buildContext(data, name, value, parms, context);
97
98             // Build default template name (classname + .vm)
99 String JavaDoc className = this.getClass().getName();
100             int pos = className.lastIndexOf(".");
101             pos = pos < 0 ? 0 : pos + 1;
102             className = className.substring(pos);
103
104             // Render the template
105 String JavaDoc template = (String JavaDoc) this.getParm("template", className + ".vm");
106             String JavaDoc templatePath = TemplateLocator.locateParameterTemplate(data, template);
107             result = TurbineVelocity.handleRequest(context, templatePath);
108         }
109         catch (Exception JavaDoc e)
110         {
111             logger.error("Exception", e);
112             // Fallback to input text box presentation style
113 result = "<input type=\"text\" name=\"" + name + "\" value=\"" + value + "\"";
114         }
115
116         TurbineVelocity.requestFinished(context);
117
118         return result;
119
120     }
121
122     /**
123      * Override this method to put your own objects in the Velocity context
124      *
125      * @param data
126      * @param name
127      * @param value
128      * @param parms
129      * @param context
130      */
131     public void buildContext(RunData data, String JavaDoc name, String JavaDoc value, Map JavaDoc parms, Context context)
132     {
133
134     }
135 }
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