/*
 * Xcm2Gxl.java
 *
 * Copyright (C) 2003 Miika Nurminen
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

import java.io.*;
import org.w3c.dom.*;
import org.w3c.dom.html.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import javax.xml.transform.dom.*;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * Representation of a xml transform filter.
 * @author  Miika Nurminen
 * @version 0.1 - 2003/10/14
 */
public class XmlTransformFramework {
  InputStream in;
  PrintStream out;
  protected Document doc;
  String docSystem = null;
  String docPublic = null;
  
  /** Creates a new instance of XmlTransformFramework */
  public XmlTransformFramework(InputStream in, PrintStream out) {
    this.in = in;
    this.out = out;
  }
  
  /** If left null, no changes are made. */
  public void setDoctype(String system,String publ) {
    docSystem = system;
    docPublic = publ;
  }
  
  protected Document newDocument(InputStream inp) throws SAXException,ParserConfigurationException,IOException {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    if (inp!=null) return builder.parse( in );
    else return builder.newDocument();
  }
  
  protected void inputData() throws SAXException,ParserConfigurationException,IOException {
    doc = newDocument(in);
  }
  
  protected void doTransform() {
  }
  
  protected void outputData() throws TransformerException {
    doc.normalize();
    DOMSource domSource = new DOMSource(doc);
    StreamResult streamResult = new StreamResult(out);
    TransformerFactory tf = TransformerFactory.newInstance();
    // XSL transformation is required to set correct doctype.
    Transformer serializer = tf.newTransformer(new StreamSource( this.getClass().getResourceAsStream("simpleoutput.xsl") /*"transformoutput.xsl"*/));
    serializer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
    if (docSystem!=null) serializer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM,docSystem);
    if (docPublic!=null) serializer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM,docPublic);
    serializer.setOutputProperty(OutputKeys.INDENT,"yes");
    serializer.transform(domSource, streamResult);
  }
  
  public void performTransform() {
    try {
      inputData();
      doTransform();
      outputData();
    }
    catch (SAXException sxe) {
      // Error generated during parsing)
      Exception  x = sxe;
      if (sxe.getException() != null) x = sxe.getException();
      ErrorLib.errorReport(x);
    } catch (ParserConfigurationException pce) {
      ErrorLib.errorReport(pce);
    }
    catch (TransformerException e) {
      ErrorLib.errorReport(e);
    }
    catch (IOException e) {
      ErrorLib.errorReport(e);
    }
  }
  
}