Is it possible to define a decorator directly in a JSP with Sitemesh?

I know I should define decorators in a configuration file or my own subclass of ConfigurableSiteMeshFilter. For example:

public class SitemeshFilter extends ConfigurableSiteMeshFilter {

    @Override
    protected void applyCustomConfiguration(final SiteMeshFilterBuilder builder) {
        builder.addDecoratorPath("/*", "/WEB-INF/views/layouts/default.jsp");
    }
}

This works for me but this isn't perfect. Can I define what decorator to use directly in a JSP file?

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page session="false" %>
<html sitemesh:decorator="layouts/default.jsp"> <!-- something like this -->
    <head>
        <title>Home</title>
        <meta content="test" name="description" />
    </head>
    <body>
        <h1>Hello world!</h1>
        ${body}
    </body>
</html>

Solution

use a meta tag

We do this all the time.

In your sitemesh.xml, allow the page to be in a meta tag named decorator like:

   <decorator-mappers>    
      <mapper class="com.opensymphony.module.sitemesh.mapper.PageDecoratorMapper">
         <param name="property.1" value="meta.decorator"/>
         <param name="property.2" value="decorator" />
      </mapper>
  </decorator-mappers>

In your decorators.xml, add a decorator like:

<decorators>
   <decorator name="default" page="/WEB-INF/decorators/default.jsp" />
   <decorator name="alternative" page="/WEB-INF/decorators/alternative.jsp" />
<decorators>

Then, in your html or jsp page, you can add a meta tag called decorator to switch between your default and alternative templates:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page session="false" %>
<html>
    <head>
        <meta name="decorator" content="alternative" />
        <title>Home</title>
        <meta content="test" name="description" />
    </head>
    <body>
        <h1>Hello world!</h1>
        ${body}
    </body>
</html>

Hope that helps...