/**
    *    Copyright 2011 meltmedia
    *
    *    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.xchain.framework.sax;
  
  import org.xml.sax.XMLReader;
  import org.xml.sax.InputSource;
  import org.xml.sax.ErrorHandler;
  import org.xml.sax.SAXParseException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * @author Mike Moulton
   * @author Christian Trimble
   * @author Josh Kennedy
   */
  public class Pipeline
  {
    public static Logger log = LoggerFactory.getLogger( Pipeline.class );
  
    protected CompositeStage compositeStage = null;
    protected InputSource source = null;
    protected XMLReader reader = null;
  
    public CompositeStage getCompositeStage() { return this.compositeStage; }
    public void setCompositeStage( CompositeStage compositeStage ) { this.compositeStage = compositeStage; }
    public void setSource( InputSource source ) { this.source = source; }
    public void setXmlReader( XMLReader reader ) { this.reader = reader; }
    public XMLReader getXmlReader() { return reader; }
  
    /**
     * Executes the pipeline.  The stage list is bound to the xml reader, then the parse method is called on the xml reader, passing
     * in the source object.  This method should only be executed once, and then the pipeline should be thrown away.
     */
    public void execute()
      throws Exception
    {
      // bind the reader to the content handler.
      reader.setContentHandler(compositeStage.getContentHandler());
  
      // attach an error handler to the transformer handler.
      reader.setErrorHandler( new ErrorHandler() {
        public void error( SAXParseException e ) {
          log.error(e.getMessage(), e);
          throw new RuntimeException("An error was thrown while processing the document.", e);
        }
  
        public void fatalError( SAXParseException e ) {
          log.error(e.getMessage(), e);
          throw new RuntimeException("A fatal error was thrown while processing the document.", e);
        }
  
        public void warning( SAXParseException e ) {
          log.warn("SAX Parser Warning.", e);
        }
      });
  
  
      if( log.isDebugEnabled() ) {
        log.debug("Running pipeline.");
      }
  
      // parse the source document.
      reader.parse(source);
    }
  }