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


1 /*
2  * Title: PageDecoratorMapper
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.*;
19
20 /**
21  * The PageDecoratorMapper allows the actual Page to determine the Decorator to be
22  * used.
23  *
24  * <p>The 'meta.decorator' and 'decorator' properties of the page are accessed
25  * and if any of them contain the name of a valid Decorator, that Decorator shall
26  * be applied.</p>
27  *
28  * <p>As an example, if HTML is being used, the Decorator could be chosen by using
29  * a <code>&lt;html decorator="mydecorator"&gt;</code> root tag <i>or</i> by using a
30  * <code>&lt;meta name="decorator" content="mydecorator"&gt;</code> tag in the header.</p>
31  *
32  * <p>The actual properties to query are specified by passing properties to the mapper using the
33  * <code>property.?</code> prefix. As the properties are stored in a Map, each key has to be unique.
34  * Example: property.1=decorator, property.2=meta.decorator .</p>
35  *
36  * @author <a HREF="mailto:joe@truemesh.com">Joe Walnes</a>
37  * @version $Revision: 1.2 $
38  *
39  * @see com.opensymphony.module.sitemesh.DecoratorMapper
40  */
41 public class PageDecoratorMapper extends AbstractDecoratorMapper {
42     private List pageProps = null;
43
44     public void init(Config config, Properties properties, DecoratorMapper parent) throws InstantiationException JavaDoc {
45         super.init(config, properties, parent);
46         pageProps = new ArrayList();
47         Iterator i = properties.entrySet().iterator();
48         while (i.hasNext()) {
49             Map.Entry entry = (Map.Entry) i.next();
50             String JavaDoc key = (String JavaDoc) entry.getKey();
51             if (key.startsWith("property")) {
52                 pageProps.add(entry.getValue());
53             }
54         }
55     }
56
57     public Decorator getDecorator(HttpServletRequest JavaDoc request, Page page) {
58         Decorator result = null;
59         Iterator i = pageProps.iterator();
60         while (i.hasNext()) {
61             String JavaDoc propName = (String JavaDoc)i.next();
62             result = getByProperty(request, page, propName);
63             if (result != null) break;
64         }
65         return result == null ? super.getDecorator(request, page) : result;
66     }
67
68     private Decorator getByProperty(HttpServletRequest JavaDoc request, Page p, String JavaDoc name) {
69         if (p.isPropertySet(name)) {
70             return getNamedDecorator(request, p.getProperty(name));
71         }
72         return null;
73     }
74 }
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