KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > opensymphony > module > sitemesh > mapper > ParameterDecoratorMapper


1 /*
2  * Title: ParameterDecoratorMapper
3  * Description:
4  *
5  * This software is published under the terms of the OpenSymphony Software
6  * License version 1.1, of which a copy has been included with this
7  * distribution in the LICENSE.txt file.
8  */
9
10 package com.opensymphony.module.sitemesh.mapper;
11
12 import com.opensymphony.module.sitemesh.Config;
13 import com.opensymphony.module.sitemesh.Decorator;
14 import com.opensymphony.module.sitemesh.DecoratorMapper;
15 import com.opensymphony.module.sitemesh.Page;
16
17 import javax.servlet.http.HttpServletRequest JavaDoc;
18 import java.util.Properties JavaDoc;
19
20 /**
21  * The ParameterDecoratorMapper will map a suitable decorator based on request
22  * parameters.
23  *
24  * <p>The ParameterDecoratorMapper is configured via three properties.
25  * <code>decorator.parameter</code> - the parameter which contains the name of the decorator which will be mapped.
26  * The default is "decorator".</p>
27  *
28  * <p>For example if <code>decorator.parameter</code> is "foobar" then
29  * myurl.jsp?foobar=mydecorator will map to the decorator named "mydecorator".</p>
30  *
31  * <p>You can also supply an optional 'confirmation parameter'.
32  * The decorator will only be mapped if the parameter named <code>parameter.name</code> is
33  * in the request URI and the value of that parameter is equal to the
34  * <code>parameter.value</code> property.</p>
35  *
36  * <p>For example assuming parameter.name=confirm and parameter.value=true
37  * the URI myurl.jsp?decorator=mydecorator&confirm=true will map the decorator mydecorator.
38  * where as the URIs myurl.jsp?decorator=mydecorator and myurl.jsp?decorator=mydecorator&confirm=false will
39  * not return any decorator.</p>
40  *
41  * @author <a HREF="mailto:mcannon@internet.com">Mike Cannon-Brookes</a>
42  * @version $Revision: 1.2 $
43  *
44  * @see com.opensymphony.module.sitemesh.DecoratorMapper
45  */
46 public class ParameterDecoratorMapper extends AbstractDecoratorMapper {
47     private String JavaDoc decoratorParameter = null, paramName = null, paramValue = null;
48
49     public void init(Config config, Properties JavaDoc properties, DecoratorMapper parent) throws InstantiationException JavaDoc {
50         super.init(config, properties, parent);
51         decoratorParameter = properties.getProperty("decorator.parameter", "decorator");
52         paramName = properties.getProperty("parameter.name", null);
53         paramValue = properties.getProperty("parameter.value", null);
54     }
55
56     public Decorator getDecorator(HttpServletRequest JavaDoc request, Page page) {
57         Decorator result = null;
58         String JavaDoc decoratorParamValue = request.getParameter(decoratorParameter);
59
60         if ((paramName == null || paramValue.equals(request.getParameter(paramName)))
61             && decoratorParamValue != null && !decoratorParamValue.trim().equals("")) {
62                 result = getNamedDecorator(request, decoratorParamValue);
63         }
64         return result == null ? super.getDecorator(request, page) : result;
65     }
66 }
Popular Tags