/*

* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Parses XML file to DOM Document

 *

*/

package com.nokia.tools.themeinstaller.xmlparser;

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import org.xml.sax.SAXException;

import com.nokia.tools.themeinstaller.logger.LogWriter;

import com.nokia.tools.themeinstaller.odtconverter.IParseOperationListener;

import com.nokia.tools.themeinstaller.odtconverter.ParseOperation;

/**

 * Parses XML File to DOM Document.

 */

public class XMLParser extends ParseOperation implements Runnable

    {

    // CONSTANTS

    // Document Builder Factory and Parser configuration

    private static final String DBF_KEY =

            "javax.xml.parsers.DocumentBuilderFactory";

    private static final String DBF_VALUE =

            "org.apache.xerces.jaxp.DocumentBuilderFactoryImpl";

    private static final String PARSER_CONFIG_KEY =

            "org.apache.xerces.xni.parser.XMLParserConfiguration";

    private static final String PARSER_CONFIG_VALUE =

            "org.apache.xerces.parsers.XIncludeAwareParserConfiguration";

    /** The Document Builder. */

    private DocumentBuilder iDocumentBuilder;

    /** XML file name */

    private String iFileName;

    /**

     * Static block.

     */

    static

        {

        // Configure the Document Builder Factory

        System.setProperty( DBF_KEY, DBF_VALUE );

        // Configure the XML Parser Configuration

        System.setProperty( PARSER_CONFIG_KEY, PARSER_CONFIG_VALUE );

        }

    /**

     * Instantiates a new XML parser without an external DTD file.

     *

     * @param aFileName the XML file name

     */

    public XMLParser( String aFileName )

        {

        this( aFileName, null );

        }

    /**

     * Instantiates a new XML parser. External DTD file can be used instead of

     * the one defined in the DOCTYPE.

     *

     * @param aFileName the XML file name

     * @param aExtDTD the DTD file name. If an external DTD is not specified,

     * Expand Entity References feature is disabled. This causes the

     * localisation to be left untouched.

     */

    public XMLParser( String aFileName, String aExtDTD )

        {

        super();

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        dbf.setNamespaceAware( true );

        try

            {

            if( aExtDTD == null )

                {

                // Disable expanding of entity references to leave localisation

                // untouched

                dbf.setExpandEntityReferences( false );

                // Disable the loading of external DTD file because expanding

                // entity references (the localisation) is disabled anyway

                dbf.setFeature(

                        "http://apache.org/xml/features/nonvalidating/load-external-dtd",

                        false );

                }

            // Enable XIncludes in XML parsing

            dbf.setXIncludeAware( true );

            // Disable the adding of XInclude parsing related attributes:

            // xml:base and xml:lang

            dbf.setFeature(

                    "http://apache.org/xml/features/xinclude/fixup-base-uris",

                    false );

            dbf.setFeature(

                    "http://apache.org/xml/features/xinclude/fixup-language",

                    false );

            // Instantiate the Document Builder for parsing

            iDocumentBuilder = dbf.newDocumentBuilder();

            if( aExtDTD != null )

                {

                // Use entity resolver for using an external DTD file

                iDocumentBuilder.setEntityResolver(

                        new DTDEntityResolver( aExtDTD ) );

                }

            }

        catch ( ParserConfigurationException e )

            {

            throw new IllegalStateException( "Could not load XML parser: " + e.toString() );

            }

        iFileName = aFileName;

        }

    /**

     * Run the XML parse operation.

     */

    public void run()

        {

        // Messages for operation listener

        int error = IParseOperationListener.OPERATION_SUCCESSFUL;

        String reason = null;

        try

            {

            // Actual parsing

            LogWriter.getInstance().logInfo(

                    this.getClass().getSimpleName() + ": Parsing " + iFileName );

            iDOMDocument = iDocumentBuilder.parse( iFileName );

            }

        catch ( SAXException e )

            {

            reason = e.getMessage();

            error = IParseOperationListener.SAX_PARSE_ERROR;

            }

        catch ( IOException e )

            {

            reason = e.getMessage();

            error = IParseOperationListener.IO_ERROR;

            }

        super.operationCompleted( error, reason );

        }

    /**

     * Starts XML parsing in a new thread.

     */

    public void parse()

        {

        Thread thread = new Thread( this );

        thread.start();

        }

    }