Superseded by Joe Mocker's Version

package net.panonet;

import java.io.File;
import java.net.URL;
import java.util.Map;

import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import com.ecyrd.jspwiki.WikiContext;

import com.ecyrd.jspwiki.plugin.WikiPlugin;
import com.ecyrd.jspwiki.plugin.PluginException;

import java.io.StringWriter;

/**
 * JSPWiki plugin for processing XML files into HTML in a Wiki page using XSLT.
 *
 * The plugin has two parameters from the perspective of the Wiki page:
 * 
 * xsl='<xslfile>'    Name of the XSLT file to use
 * xml='<xslfile>'    Name of the XML file to process
 *
 * 29.05.2004 Jan Wessely <info@jawe.net>: Relative paths are resolved to the wiki's base URL.
 */
public class XSLTPlugin implements WikiPlugin
{
    /**
     * Main plugin entry point.
     */
    public String execute(WikiContext context,
                          Map params)
        throws PluginException
    {
        // Get the names of the XML and XSL files to use
        String xsl = getAbsolutePath((String)params.get( "xsl" ), context);
        String xml = getAbsolutePath((String)params.get( "xml" ), context);
		
        String result = "";
        
        try
        {
            // Create a Transformer
            TransformerFactory transformerFactory
                = TransformerFactory.newInstance();
            Transformer transformer
                = transformerFactory.newTransformer( new StreamSource( xsl ) );

            // Transform the given XML file using the given XSL file, placing
            // it in a String.
            StringWriter resultWriter = new StringWriter();
        
            transformer.transform( new StreamSource( xml ),
                                   new StreamResult( resultWriter ) );
            
            result = resultWriter.toString();
        }
        catch( Exception e )
        {
            System.out.println( e.toString() );
            throw new PluginException( "Exception performing transformation.",
                                       e );
        }
        
        return result;
    }
	
    private String getAbsolutePath(String path, WikiContext context) {
        if (!(path.startsWith("http:")
                || path.startsWith("file:"))) {
            path = context.getEngine().getBaseURL()
                    + (path.startsWith("/") ? path : "/" + path);
        } else if (path.startsWith("file:")) {
            throw new IllegalArgumentException("file: URLs are not allowed.");
        }
        return path;
    }
}