/*
 * Copyright 2005 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.wamblee.xml;

import java.io.ByteArrayInputStream;
import java.io.File;

import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamSource;

import org.w3c.dom.Document;

/**
 * XSLT utilities.
 */
public class XSLT {

    /**
     * Transforms a DOM document into another DOM document using a given XSLT
     * transformation.
     * 
     * @param aDocument
     *            Document to transform.
     * @param aXslt
     *            XSLT to use.
     * @return Transformed document.
     */
    public static Document transform( Document aDocument, File aXslt ) {
        Source source = new DOMSource( aDocument );
        DOMResult result = new DOMResult( );
        transform( source, result, aXslt );
        return (Document) result.getNode( );
    }
    
    public static Document transform(byte[] aDocument, File aXslt ) {
        Source source = new StreamSource( new ByteArrayInputStream(aDocument) );
        DOMResult result = new DOMResult( );
        transform( source, result, aXslt );
        return (Document) result.getNode( );
    }

    /**
     * Transforms a DOM document into another DOM document using a given XSLT
     * transformation.
     * 
     * @param aDocument
     *            Document to transform.
     * @param aXslt
     *            XSLT to use.
     * @return Transformed document.
     */
    public static void transform( Source aSource, Result aResult,
            File aXslt ) {
        try {
            Source xslt = new StreamSource( aXslt );
            Transformer transformer = TransformerFactory.newInstance( )
                    .newTransformer( xslt );
            transformer.transform( aSource, aResult );
        } catch ( TransformerConfigurationException e ) {
            throw new RuntimeException(
                    "Configuration problem of XSLT transformation", e );
        } catch ( TransformerException e ) {
            throw new RuntimeException( "Error transforming document", e );
        }
    }
}