// 
   //Copyright (c) 2003, 2004, Caltha - Gajda, Krzewski, Mach, Potempski Sp.J. 
   //All rights reserved. 
   //   
   //Redistribution and use in source and binary forms, with or without modification,  
   //are permitted provided that the following conditions are met: 
   //   
   //* Redistributions of source code must retain the above copyright notice,  
   //this list of conditions and the following disclaimer. 
  //* Redistributions in binary form must reproduce the above copyright notice,  
  //this list of conditions and the following disclaimer in the documentation  
  //and/or other materials provided with the distribution. 
  //* Neither the name of the Caltha - Gajda, Krzewski, Mach, Potempski Sp.J.  
  //nor the names of its contributors may be used to endorse or promote products  
  //derived from this software without specific prior written permission. 
  //
  //THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"  
  //AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED  
  //WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
  //IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,  
  //INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,  
  //BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
  //OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,  
  //WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)  
  //ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE  
  //POSSIBILITY OF SUCH DAMAGE. 
  //
  package org.objectledge.xml;
  
  import org.xml.sax.EntityResolver;
  import org.xml.sax.InputSource;
  import org.xml.sax.Locator;
  import org.xml.sax.SAXException;
  
  import com.sun.msv.reader.GrammarReaderController;
  
  /**
   * GrammarReaderController that logs all warnings and throws exceptions on errors.
   *
   * @author <a href="mailto:dgajda@caltha.pl">Damian Gajda</a>
   * @version $Id: BaseGrammarReaderController.java,v 1.3 2005/02/21 16:27:51 zwierzem Exp $
   */
  public abstract class BaseGrammarReaderController implements GrammarReaderController
  {
  	/*** Loaded grammar URI. */
  	private String grammarUri;
  	
      /*** Entity resolution is delegated to this object, it can be <code>null</null>. */
      private EntityResolver entityResolver;
  
      /*** Used to compose information of location of errors and warnings. */
      private StringBuilder locationMessage = new StringBuilder(64);
  
  	/***
  	 * Creates a grammar reader controller.
  	 * 
  	 * @param grammarUri URI of a loaded grammar - provided for better warning description
  	 * @param entityResolver optional entity resolver.
  	 */
      public BaseGrammarReaderController(
          String grammarUri,
          EntityResolver entityResolver)
      {
      	this.grammarUri = grammarUri;
          this.entityResolver = entityResolver;
      }
  
  	/***
  	 * Creates a grammar reader controller without entity resolver.
  	 * 
  	 * @param grammarUri URI of a loaded grammar - provided for better warning description
  	 */
      public BaseGrammarReaderController(String grammarUri)
      {
          this(grammarUri, null);
      }
  	
      //------------------------------------------------------------------------
      // EntityResolver methods
  
      /***
       * Resolves an entity, uses externaly set EntityResolver or returns <code>null</code>.
       * 
       * @param publicId public id of an entity 
       * @param systemId system id of an entity
       * @return resolved entity's input source 
       * @throws java.io.IOException on IO errors while resolving entity
       * @throws SAXException on parsing errors while resolving entity
       */
      public InputSource resolveEntity( String publicId, String systemId )
  	    throws java.io.IOException, SAXException
      {
          if(entityResolver!=null)
          {
              return entityResolver.resolveEntity(publicId, systemId);
          }
          else
          {
              return null;
         }
     }
 
     //------------------------------------------------------------------------
     // GrammarReaderController methods
 
     /***
      * Receives warning notification - does nothing.
      * 
      * @param loc warning location info
      * @param errorMessage warning message
      */
     public void warning(Locator[] loc, String errorMessage)
     {
         // pass to the log?
     }
 
     /***
      * Receives error notification - does nothing.
      * 
      * @param loc error location info
      * @param errorMessage error message
      * @param nestedException exception nested in error information
      */
     public void error( Locator[] loc, String errorMessage, Exception nestedException )
     {
         // TODO pass the log?
     }
 
     //------------------------------------------------------------------------
     // Utility methods
 
 	/***
 	 * Prepares a location message.
 	 * 
 	 * @param type message type - 'error' or 'warning'
 	 * @param loc locator of the error or warning
 	 * @param errorMessage a message
 	 * @return formatted location message
 	 */
     protected String getLocationMessage(String type, Locator[] loc, String errorMessage)
     {
         // init buffer
         locationMessage.setLength(0);
 
 		
 		locationMessage.append(type);
 		locationMessage.append(" on schema '").append(grammarUri).append("' ; ");
 
         locationMessage.append(errorMessage);
         locationMessage.append(" ; ");
 
         if(loc == null || loc.length == 0)
         {
             locationMessage.append("location unknown");
         }
         else
         {
             for( int i=0; i<loc.length; i++ )
             {
                 getLocation(loc[i]);
             }
         }
 
         return locationMessage.toString();
     }
 
     private void getLocation(Locator loc)
     {
         if(loc.getColumnNumber()>=0)
         {
             locationMessage.append("column:");
             locationMessage.append(loc.getColumnNumber());
         }
 
         locationMessage.append(" line:");
         locationMessage.append(loc.getLineNumber());
         locationMessage.append("   ");
         locationMessage.append(loc.getSystemId());
         locationMessage.append("  ");
     }
 }