/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.xerces.impl.xs.opti;

import java.io.IOException;
import java.util.Locale;

import org.apache.xerces.impl.Constants;
import org.apache.xerces.impl.XML11DTDScannerImpl;
import org.apache.xerces.impl.XML11NSDocumentScannerImpl;
import org.apache.xerces.impl.XMLDTDScannerImpl;
import org.apache.xerces.impl.XMLEntityHandler;
import org.apache.xerces.impl.XMLEntityManager;
import org.apache.xerces.impl.XMLErrorReporter;
import org.apache.xerces.impl.XMLNSDocumentScannerImpl;
import org.apache.xerces.impl.XMLVersionDetector;
import org.apache.xerces.impl.dv.DTDDVFactory;
import org.apache.xerces.impl.msg.XMLMessageFormatter;
import org.apache.xerces.impl.validation.ValidationManager;
import org.apache.xerces.impl.xs.XSMessageFormatter;
import org.apache.xerces.parsers.BasicParserConfiguration;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.xni.XMLLocator;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.grammars.XMLGrammarPool;
import org.apache.xerces.xni.parser.XMLComponent;
import org.apache.xerces.xni.parser.XMLComponentManager;
import org.apache.xerces.xni.parser.XMLConfigurationException;
import org.apache.xerces.xni.parser.XMLDTDScanner;
import org.apache.xerces.xni.parser.XMLDocumentScanner;
import org.apache.xerces.xni.parser.XMLInputSource;
import org.apache.xerces.xni.parser.XMLPullParserConfiguration;

/**
 * @xerces.internal  
 * 
 * @author Rahul Srivastava, Sun Microsystems Inc.
 *
 * @version $Id$
 */
public class SchemaParsingConfig extends BasicParserConfiguration 
    implements XMLPullParserConfiguration {
    
    //
    // Constants
    //
    
    protected final static String XML11_DATATYPE_VALIDATOR_FACTORY =
        "org.apache.xerces.impl.dv.dtd.XML11DTDDVFactoryImpl";
    
    // feature identifiers
    
    /** Feature identifier: warn on duplicate attribute definition. */
    protected static final String WARN_ON_DUPLICATE_ATTDEF =
        Constants.XERCES_FEATURE_PREFIX + Constants.WARN_ON_DUPLICATE_ATTDEF_FEATURE;
    
    /** Feature identifier: warn on duplicate entity definition. */
    //  protected static final String WARN_ON_DUPLICATE_ENTITYDEF = Constants.XERCES_FEATURE_PREFIX + Constants.WARN_ON_DUPLICATE_ENTITYDEF_FEATURE;
    
    /** Feature identifier: warn on undeclared element definition. */
    protected static final String WARN_ON_UNDECLARED_ELEMDEF =
        Constants.XERCES_FEATURE_PREFIX + Constants.WARN_ON_UNDECLARED_ELEMDEF_FEATURE;
    
    /** Feature identifier: allow Java encodings. */
    protected static final String ALLOW_JAVA_ENCODINGS = 
        Constants.XERCES_FEATURE_PREFIX + Constants.ALLOW_JAVA_ENCODINGS_FEATURE;
    
    /** Feature identifier: continue after fatal error. */
    protected static final String CONTINUE_AFTER_FATAL_ERROR = 
        Constants.XERCES_FEATURE_PREFIX + Constants.CONTINUE_AFTER_FATAL_ERROR_FEATURE;
    
    /** Feature identifier: load external DTD. */
    protected static final String LOAD_EXTERNAL_DTD =
        Constants.XERCES_FEATURE_PREFIX + Constants.LOAD_EXTERNAL_DTD_FEATURE;
    
    /** Feature identifier: notify built-in refereces. */
    protected static final String NOTIFY_BUILTIN_REFS =
        Constants.XERCES_FEATURE_PREFIX + Constants.NOTIFY_BUILTIN_REFS_FEATURE;
    
    /** Feature identifier: notify character refereces. */
    protected static final String NOTIFY_CHAR_REFS =
        Constants.XERCES_FEATURE_PREFIX + Constants.NOTIFY_CHAR_REFS_FEATURE;
    
    /** Feature identifier: expose schema normalized value */
    protected static final String NORMALIZE_DATA =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_NORMALIZED_VALUE;
    
    /** Feature identifier: send element default value via characters() */
    protected static final String SCHEMA_ELEMENT_DEFAULT =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_ELEMENT_DEFAULT;
    
    /** Feature identifier: generate synthetic annotations. */
    protected static final String GENERATE_SYNTHETIC_ANNOTATIONS = 
        Constants.XERCES_FEATURE_PREFIX + Constants.GENERATE_SYNTHETIC_ANNOTATIONS_FEATURE;
    
    
    // property identifiers
    
    /** Property identifier: error reporter. */
    protected static final String ERROR_REPORTER = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.ERROR_REPORTER_PROPERTY;
    
    /** Property identifier: entity manager. */
    protected static final String ENTITY_MANAGER = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.ENTITY_MANAGER_PROPERTY;
    
    /** Property identifier document scanner: */
    protected static final String DOCUMENT_SCANNER = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.DOCUMENT_SCANNER_PROPERTY;
    
    /** Property identifier: DTD scanner. */
    protected static final String DTD_SCANNER = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.DTD_SCANNER_PROPERTY;
    
    /** Property identifier: grammar pool. */
    protected static final String XMLGRAMMAR_POOL = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.XMLGRAMMAR_POOL_PROPERTY;
    
    /** Property identifier: DTD validator. */
    protected static final String DTD_VALIDATOR = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.DTD_VALIDATOR_PROPERTY;
    
    /** Property identifier: namespace binder. */
    protected static final String NAMESPACE_BINDER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.NAMESPACE_BINDER_PROPERTY;
    
    /** Property identifier: datatype validator factory. */
    protected static final String DATATYPE_VALIDATOR_FACTORY = 
        Constants.XERCES_PROPERTY_PREFIX + Constants.DATATYPE_VALIDATOR_FACTORY_PROPERTY;
    
    protected static final String VALIDATION_MANAGER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.VALIDATION_MANAGER_PROPERTY;
    
    /** Property identifier: XML Schema validator. */
    protected static final String SCHEMA_VALIDATOR =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SCHEMA_VALIDATOR_PROPERTY;
    
    /** Property identifier: locale. */
    protected static final String LOCALE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.LOCALE_PROPERTY;
    
    
    // debugging
    
    /** Set to true and recompile to print exception stack trace. */
    private static final boolean PRINT_EXCEPTION_STACK_TRACE = false;
    
    //
    // Data
    //
    
    //
    // XML 1.0 components
    //
    
    /** The XML 1.0 Datatype validator factory. */
    protected final DTDDVFactory fDatatypeValidatorFactory;
    
    /** The XML 1.0 Document scanner. */
    protected final XMLNSDocumentScannerImpl fNamespaceScanner;
    
    /** The XML 1.0 DTD scanner. */
    protected final XMLDTDScannerImpl fDTDScanner;
    
    //
    // XML 1.1 components
    //
    
    /** The XML 1.1 Datatype validator factory. */
    protected DTDDVFactory fXML11DatatypeFactory = null;
    
    /** The XML 1.1 Document scanner. */
    protected XML11NSDocumentScannerImpl fXML11NSDocScanner = null;
    
    /** The XML 1.1 DTD scanner. **/
    protected XML11DTDScannerImpl fXML11DTDScanner = null;
    
    // common components (non-configurable)
    
    /** Current Datatype validator factory. */
    protected DTDDVFactory fCurrentDVFactory;
    
    /** Current scanner */
    protected XMLDocumentScanner fCurrentScanner;
    
    /** Current DTD scanner. */
    protected XMLDTDScanner fCurrentDTDScanner;
    
    /** Grammar pool. */
    protected XMLGrammarPool fGrammarPool;
    
    /** XML version detector. */
    protected final XMLVersionDetector fVersionDetector;
    
    // common components (configurable)
    
    /** Error reporter. */
    protected final XMLErrorReporter fErrorReporter;
    
    /** Entity manager. */
    protected final XMLEntityManager fEntityManager;
    
    /** Input Source */
    protected XMLInputSource fInputSource;
    
    protected final ValidationManager fValidationManager;
    // state
    
    /** Locator */
    protected XMLLocator fLocator;
    
    /** 
     * True if a parse is in progress. This state is needed because
     * some features/properties cannot be set while parsing (e.g.
     * validation and namespaces).
     */
    protected boolean fParseInProgress = false;
    
    /** 
     * fConfigUpdated is set to true if there has been any change to the configuration settings, 
     * i.e a feature or a property was changed.
     */
    protected boolean fConfigUpdated = false;
    
    /** Flag indiciating whether XML11 components have been initialized. */
    private boolean f11Initialized = false;
    
    //
    // Constructors
    //
    
    /** Default constructor. */
    public SchemaParsingConfig() {
        this(null, null, null);
    } // <init>()
    
    /** 
     * Constructs a parser configuration using the specified symbol table. 
     *
     * @param symbolTable The symbol table to use.
     */
    public SchemaParsingConfig(SymbolTable symbolTable) {
        this(symbolTable, null, null);
    } // <init>(SymbolTable)
    
    /**
     * Constructs a parser configuration using the specified symbol table and
     * grammar pool.
     * <p>
     * <strong>REVISIT:</strong> 
     * Grammar pool will be updated when the new validation engine is
     * implemented.
     *
     * @param symbolTable The symbol table to use.
     * @param grammarPool The grammar pool to use.
     */
    public SchemaParsingConfig(SymbolTable symbolTable,
            XMLGrammarPool grammarPool) {
        this(symbolTable, grammarPool, null);
    } // <init>(SymbolTable,XMLGrammarPool)
    
    /**
     * Constructs a parser configuration using the specified symbol table,
     * grammar pool, and parent settings.
     * <p>
     * <strong>REVISIT:</strong> 
     * Grammar pool will be updated when the new validation engine is
     * implemented.
     *
     * @param symbolTable    The symbol table to use.
     * @param grammarPool    The grammar pool to use.
     * @param parentSettings The parent settings.
     */
    public SchemaParsingConfig(SymbolTable symbolTable,
            XMLGrammarPool grammarPool,
            XMLComponentManager parentSettings) {
        super(symbolTable, parentSettings);
        
        // add default recognized features
        final String[] recognizedFeatures = {
            PARSER_SETTINGS, WARN_ON_DUPLICATE_ATTDEF,   WARN_ON_UNDECLARED_ELEMDEF,
            ALLOW_JAVA_ENCODINGS,       CONTINUE_AFTER_FATAL_ERROR,
            LOAD_EXTERNAL_DTD,          NOTIFY_BUILTIN_REFS,
            NOTIFY_CHAR_REFS, GENERATE_SYNTHETIC_ANNOTATIONS
        };
        addRecognizedFeatures(recognizedFeatures);
        fFeatures.put(PARSER_SETTINGS, Boolean.TRUE);
        // set state for default features
        fFeatures.put(WARN_ON_DUPLICATE_ATTDEF, Boolean.FALSE);
        //setFeature(WARN_ON_DUPLICATE_ENTITYDEF, false);
        fFeatures.put(WARN_ON_UNDECLARED_ELEMDEF, Boolean.FALSE);
        fFeatures.put(ALLOW_JAVA_ENCODINGS, Boolean.FALSE);
        fFeatures.put(CONTINUE_AFTER_FATAL_ERROR, Boolean.FALSE);
        fFeatures.put(LOAD_EXTERNAL_DTD, Boolean.TRUE);
        fFeatures.put(NOTIFY_BUILTIN_REFS, Boolean.FALSE);
        fFeatures.put(NOTIFY_CHAR_REFS, Boolean.FALSE);
        fFeatures.put(GENERATE_SYNTHETIC_ANNOTATIONS, Boolean.FALSE);
        
        // add default recognized properties
        final String[] recognizedProperties = {
            ERROR_REPORTER,             
            ENTITY_MANAGER, 
            DOCUMENT_SCANNER,
            DTD_SCANNER,
            DTD_VALIDATOR,
            NAMESPACE_BINDER,
            XMLGRAMMAR_POOL,   
            DATATYPE_VALIDATOR_FACTORY,
            VALIDATION_MANAGER,
            GENERATE_SYNTHETIC_ANNOTATIONS,
            LOCALE
        };
        addRecognizedProperties(recognizedProperties);
        
        fGrammarPool = grammarPool;
        if (fGrammarPool != null) {
            setProperty(XMLGRAMMAR_POOL, fGrammarPool);
        }
        
        fEntityManager = new XMLEntityManager();
        fProperties.put(ENTITY_MANAGER, fEntityManager);
        addComponent(fEntityManager);
        
        fErrorReporter = new XMLErrorReporter();
        fErrorReporter.setDocumentLocator(fEntityManager.getEntityScanner());
        fProperties.put(ERROR_REPORTER, fErrorReporter);
        addComponent(fErrorReporter);
        
        fNamespaceScanner = new XMLNSDocumentScannerImpl();
        fProperties.put(DOCUMENT_SCANNER, fNamespaceScanner);
        addRecognizedParamsAndSetDefaults(fNamespaceScanner);
        
        fDTDScanner = new XMLDTDScannerImpl();
        fProperties.put(DTD_SCANNER, fDTDScanner);
        addRecognizedParamsAndSetDefaults(fDTDScanner);
        
        fDatatypeValidatorFactory = DTDDVFactory.getInstance();
        fProperties.put(DATATYPE_VALIDATOR_FACTORY,
                fDatatypeValidatorFactory);
        
        fValidationManager = new ValidationManager();
        fProperties.put(VALIDATION_MANAGER, fValidationManager);
        
        fVersionDetector = new XMLVersionDetector();
        
        // add message formatters
        if (fErrorReporter.getMessageFormatter(XMLMessageFormatter.XML_DOMAIN) == null) {
            XMLMessageFormatter xmft = new XMLMessageFormatter();
            fErrorReporter.putMessageFormatter(XMLMessageFormatter.XML_DOMAIN, xmft);
            fErrorReporter.putMessageFormatter(XMLMessageFormatter.XMLNS_DOMAIN, xmft);
        }
        
        if (fErrorReporter.getMessageFormatter(XSMessageFormatter.SCHEMA_DOMAIN) == null) {
            XSMessageFormatter xmft = new XSMessageFormatter();
            fErrorReporter.putMessageFormatter(XSMessageFormatter.SCHEMA_DOMAIN, xmft);
        }
        
        // set locale
        try {
            setLocale(Locale.getDefault()); 
        }
        catch (XNIException e) {
            // do nothing
            // REVISIT: What is the right thing to do? -Ac
        }
        
    } // <init>(SymbolTable,XMLGrammarPool)
    
    //
    // Public methods
    //
    
    /**
     * Returns the state of a feature.
     * 
     * @param featureId The feature identifier.
     * @return true if the feature is supported
     * 
     * @throws XMLConfigurationException Thrown for configuration error.
     *                                   In general, components should
     *                                   only throw this exception if
     *                                   it is <strong>really</strong>
     *                                   a critical error.
     */
    public boolean getFeature(String featureId)
        throws XMLConfigurationException {
        // make this feature special
        if (featureId.equals(PARSER_SETTINGS)) {
            return fConfigUpdated;
        }
        return super.getFeature(featureId);

    } // getFeature(String):boolean
    
    /**
     * Set the state of a feature.
     *
     * Set the state of any feature in a SAX2 parser.  The parser
     * might not recognize the feature, and if it does recognize
     * it, it might not be able to fulfill the request.
     *
     * @param featureId The unique identifier (URI) of the feature.
     * @param state The requested state of the feature (true or false).
     *
     * @exception org.apache.xerces.xni.parser.XMLConfigurationException If the
     *            requested feature is not known.
     */
    public void setFeature(String featureId, boolean state)
        throws XMLConfigurationException {
        
        fConfigUpdated = true;
        
        // forward to every XML 1.0 component
        fNamespaceScanner.setFeature(featureId, state);
        fDTDScanner.setFeature(featureId, state);
        
        // forward to every XML 1.1 component
        if (f11Initialized) {
            try {
                fXML11DTDScanner.setFeature(featureId, state);
            }
            // ignore the exception.
            catch (Exception e) {}
            try {
                fXML11NSDocScanner.setFeature(featureId, state);
            }
            // ignore the exception
            catch (Exception e) {}
        }
        
        // save state if noone "objects"
        super.setFeature(featureId, state);

    } // setFeature(String,boolean)
    
    /**
     * Returns the value of a property.
     * 
     * @param propertyId The property identifier.
     * @return the value of the property
     * 
     * @throws XMLConfigurationException Thrown for configuration error.
     *                                   In general, components should
     *                                   only throw this exception if
     *                                   it is <strong>really</strong>
     *                                   a critical error.
     */
    public Object getProperty(String propertyId)
        throws XMLConfigurationException {
        if (LOCALE.equals(propertyId)) {
            return getLocale();
        }
        return super.getProperty(propertyId);
    }
    
    /**
     * setProperty
     * 
     * @param propertyId 
     * @param value 
     */
    public void setProperty(String propertyId, Object value)
        throws XMLConfigurationException {
        
        fConfigUpdated = true;
        if (LOCALE.equals(propertyId)) {
            setLocale((Locale) value);
        }
        
        // forward to every XML 1.0 component
        fNamespaceScanner.setProperty(propertyId, value);
        fDTDScanner.setProperty(propertyId, value);
        
        // forward to every XML 1.1 component
        if (f11Initialized) {
            try {
                fXML11DTDScanner.setProperty(propertyId, value);
            }
            // ignore the exception.
            catch (Exception e) {}
            try {
                fXML11NSDocScanner.setProperty(propertyId, value);
            }
            // ignore the exception
            catch (Exception e) {}
        }

        // store value if noone "objects"
        super.setProperty(propertyId, value);

    } // setProperty(String,Object)
    
    /**
     * Set the locale to use for messages.
     *
     * @param locale The locale object to use for localization of messages.
     *
     * @exception XNIException Thrown if the parser does not support the
     *                         specified locale.
     */
    public void setLocale(Locale locale) throws XNIException {
        super.setLocale(locale);
        fErrorReporter.setLocale(locale);
    } // setLocale(Locale)
    
    //
    // XMLPullParserConfiguration methods
    //
    
    // parsing
    
    /**
     * Sets the input source for the document to parse.
     *
     * @param inputSource The document's input source.
     *
     * @exception XMLConfigurationException Thrown if there is a 
     *                        configuration error when initializing the
     *                        parser.
     * @exception IOException Thrown on I/O error.
     *
     * @see #parse(boolean)
     */
    public void setInputSource(XMLInputSource inputSource)
    throws XMLConfigurationException, IOException {
        
        // REVISIT: this method used to reset all the components and
        //          construct the pipeline. Now reset() is called
        //          in parse (boolean) just before we parse the document
        //          Should this method still throw exceptions..?
        
        fInputSource = inputSource;
        
    } // setInputSource(XMLInputSource)
    
    /**
     * Parses the document in a pull parsing fashion.
     *
     * @param complete True if the pull parser should parse the
     *                 remaining document completely.
     *
     * @return True if there is more document to parse.
     *
     * @exception XNIException Any XNI exception, possibly wrapping 
     *                         another exception.
     * @exception IOException  An IO exception from the parser, possibly
     *                         from a byte stream or character stream
     *                         supplied by the parser.
     *
     * @see #setInputSource
     */
    public boolean parse(boolean complete) throws XNIException, IOException {
        //
        // reset and configure pipeline and set InputSource.
        if (fInputSource != null) {
            try {
                fValidationManager.reset();
                fVersionDetector.reset(this);
                reset();

                short version = fVersionDetector.determineDocVersion(fInputSource);
                // XML 1.0
                if (version == Constants.XML_VERSION_1_0) {
                    configurePipeline();
                    resetXML10();
                }
                // XML 1.1
                else if (version == Constants.XML_VERSION_1_1) {
                    initXML11Components();
                    configureXML11Pipeline();
                    resetXML11();
                }
                // Unrecoverable error reported during version detection
                else {
                   return false;
                }
                
                // mark configuration as fixed
                fConfigUpdated = false;

                // resets and sets the pipeline.
                fVersionDetector.startDocumentParsing((XMLEntityHandler) fCurrentScanner, version);
                fInputSource = null;
            } 
            catch (XNIException ex) {
                if (PRINT_EXCEPTION_STACK_TRACE)
                    ex.printStackTrace();
                throw ex;
            } 
            catch (IOException ex) {
                if (PRINT_EXCEPTION_STACK_TRACE)
                    ex.printStackTrace();
                throw ex;
            } 
            catch (RuntimeException ex) {
                if (PRINT_EXCEPTION_STACK_TRACE)
                    ex.printStackTrace();
                throw ex;
            }
            catch (Exception ex) {
                if (PRINT_EXCEPTION_STACK_TRACE)
                    ex.printStackTrace();
                throw new XNIException(ex);
            }
        }
        
        try {
            return fCurrentScanner.scanDocument(complete);
        } 
        catch (XNIException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        } 
        catch (IOException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        } 
        catch (RuntimeException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        }
        catch (Exception ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw new XNIException(ex);
        }
        
    } // parse(boolean):boolean
    
    /**
     * If the application decides to terminate parsing before the xml document
     * is fully parsed, the application should call this method to free any
     * resource allocated during parsing. For example, close all opened streams.
     */
    public void cleanup() {
        fEntityManager.closeReaders();
    }
    
    //
    // XMLParserConfiguration methods
    //
    
    /**
     * Parses the specified input source.
     *
     * @param source The input source.
     *
     * @exception XNIException Throws exception on XNI error.
     * @exception java.io.IOException Throws exception on i/o error.
     */
    public void parse(XMLInputSource source) throws XNIException, IOException {
        
        if (fParseInProgress) {
            // REVISIT - need to add new error message
            throw new XNIException("FWK005 parse may not be called while parsing.");
        }
        fParseInProgress = true;
        
        try {
            setInputSource(source);
            parse(true);
        } 
        catch (XNIException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        } 
        catch (IOException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        }
        catch (RuntimeException ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw ex;
        }              
        catch (Exception ex) {
            if (PRINT_EXCEPTION_STACK_TRACE)
                ex.printStackTrace();
            throw new XNIException(ex);
        }
        finally {
            fParseInProgress = false;
            // close all streams opened by xerces
            this.cleanup();
        }
        
    } // parse(InputSource)
    
    //
    // Protected methods
    //
    
    /** 
     * Reset all components before parsing. 
     *
     * @throws XNIException Thrown if an error occurs during initialization.
     */
    public void reset() throws XNIException {
        
        // initialize the common components
        super.reset();
        
    } // reset()
    
    /** Configures the XML 1.0 pipeline. */
    protected void configurePipeline() {
        
        if (fCurrentDVFactory != fDatatypeValidatorFactory) {
            fCurrentDVFactory = fDatatypeValidatorFactory;
            // use XML 1.0 datatype library
            setProperty(DATATYPE_VALIDATOR_FACTORY, fCurrentDVFactory);
        }
        
        // setup document pipeline
        if (fCurrentScanner != fNamespaceScanner) {
            fCurrentScanner = fNamespaceScanner;
            setProperty(DOCUMENT_SCANNER, fCurrentScanner);
        }
        fNamespaceScanner.setDocumentHandler(fDocumentHandler);
        if (fDocumentHandler != null) {
            fDocumentHandler.setDocumentSource(fNamespaceScanner);
        }
        fLastComponent = fNamespaceScanner;
        
        // setup dtd pipeline
        if (fCurrentDTDScanner != fDTDScanner) {
            fCurrentDTDScanner = fDTDScanner;
            setProperty(DTD_SCANNER, fCurrentDTDScanner);
        }
        fDTDScanner.setDTDHandler(fDTDHandler);
        if (fDTDHandler != null) {
            fDTDHandler.setDTDSource(fDTDScanner);
        }
        fDTDScanner.setDTDContentModelHandler(fDTDContentModelHandler);
        if (fDTDContentModelHandler != null) {
            fDTDContentModelHandler.setDTDContentModelSource(fDTDScanner);
        } 
        
    } // configurePipeline()
    
    /** Configures the XML 1.1 pipeline. */
    protected void configureXML11Pipeline() {
        
        if (fCurrentDVFactory != fXML11DatatypeFactory) {
            fCurrentDVFactory = fXML11DatatypeFactory;
            // use XML 1.1 datatype library
            setProperty(DATATYPE_VALIDATOR_FACTORY, fCurrentDVFactory);
        }
        
        // setup document pipeline
        if (fCurrentScanner != fXML11NSDocScanner) {
            fCurrentScanner = fXML11NSDocScanner;
            setProperty(DOCUMENT_SCANNER, fCurrentScanner);
        }
        fXML11NSDocScanner.setDocumentHandler(fDocumentHandler);
        if (fDocumentHandler != null) {
            fDocumentHandler.setDocumentSource(fXML11NSDocScanner);
        }
        fLastComponent = fXML11NSDocScanner;
        
        // setup dtd pipeline
        if (fCurrentDTDScanner != fXML11DTDScanner) {
            fCurrentDTDScanner = fXML11DTDScanner;
            setProperty(DTD_SCANNER, fCurrentDTDScanner);
        }
        fXML11DTDScanner.setDTDHandler(fDTDHandler);
        if (fDTDHandler != null) {
            fDTDHandler.setDTDSource(fXML11DTDScanner);
        }
        fXML11DTDScanner.setDTDContentModelHandler(fDTDContentModelHandler);
        if (fDTDContentModelHandler != null) {
            fDTDContentModelHandler.setDTDContentModelSource(fXML11DTDScanner);
        } 
        
    } // configureXML11Pipeline()
    
    // features and properties
    
    /**
     * Check a feature. If feature is know and supported, this method simply
     * returns. Otherwise, the appropriate exception is thrown.
     *
     * @param featureId The unique identifier (URI) of the feature.
     *
     * @throws XMLConfigurationException Thrown for configuration error.
     *                                   In general, components should
     *                                   only throw this exception if
     *                                   it is <strong>really</strong>
     *                                   a critical error.
     */
    protected void checkFeature(String featureId)
        throws XMLConfigurationException {
        
        //
        // Xerces Features
        //
        
        if (featureId.startsWith(Constants.XERCES_FEATURE_PREFIX)) {
            final int suffixLength = featureId.length() - Constants.XERCES_FEATURE_PREFIX.length();
            
            //
            // http://apache.org/xml/features/validation/dynamic
            //   Allows the parser to validate a document only when it
            //   contains a grammar. Validation is turned on/off based
            //   on each document instance, automatically.
            //
            if (suffixLength == Constants.DYNAMIC_VALIDATION_FEATURE.length() && 
                    featureId.endsWith(Constants.DYNAMIC_VALIDATION_FEATURE)) {
                return;
            }
            //
            // http://apache.org/xml/features/validation/default-attribute-values
            //
            if (suffixLength == Constants.DEFAULT_ATTRIBUTE_VALUES_FEATURE.length() && 
                    featureId.endsWith(Constants.DEFAULT_ATTRIBUTE_VALUES_FEATURE)) {
                // REVISIT
                short type = XMLConfigurationException.NOT_SUPPORTED;
                throw new XMLConfigurationException(type, featureId);
            }
            //
            // http://apache.org/xml/features/validation/default-attribute-values
            //
            if (suffixLength == Constants.VALIDATE_CONTENT_MODELS_FEATURE.length() && 
                    featureId.endsWith(Constants.VALIDATE_CONTENT_MODELS_FEATURE)) {
                // REVISIT
                short type = XMLConfigurationException.NOT_SUPPORTED;
                throw new XMLConfigurationException(type, featureId);
            }
            //
            // http://apache.org/xml/features/validation/nonvalidating/load-dtd-grammar
            //
            if (suffixLength == Constants.LOAD_DTD_GRAMMAR_FEATURE.length() && 
                    featureId.endsWith(Constants.LOAD_DTD_GRAMMAR_FEATURE)) {
                return;
            }
            //
            // http://apache.org/xml/features/validation/nonvalidating/load-external-dtd
            //
            if (suffixLength == Constants.LOAD_EXTERNAL_DTD_FEATURE.length() && 
                    featureId.endsWith(Constants.LOAD_EXTERNAL_DTD_FEATURE)) {
                return;
            }
            
            //
            // http://apache.org/xml/features/validation/default-attribute-values
            //
            if (suffixLength == Constants.VALIDATE_DATATYPES_FEATURE.length() &&
                    featureId.endsWith(Constants.VALIDATE_DATATYPES_FEATURE)) {
                short type = XMLConfigurationException.NOT_SUPPORTED;
                throw new XMLConfigurationException(type, featureId);
            }
        }
        
        //
        // Not recognized
        //
        
        super.checkFeature(featureId);
        
    } // checkFeature(String)
    
    /**
     * Check a property. If the property is know and supported, this method
     * simply returns. Otherwise, the appropriate exception is thrown.
     *
     * @param propertyId The unique identifier (URI) of the property
     *                   being set.
     *
     * @throws XMLConfigurationException Thrown for configuration error.
     *                                   In general, components should
     *                                   only throw this exception if
     *                                   it is <strong>really</strong>
     *                                   a critical error.
     */
    protected void checkProperty(String propertyId)
        throws XMLConfigurationException {
        
        //
        // Xerces Properties
        //
        
        if (propertyId.startsWith(Constants.XERCES_PROPERTY_PREFIX)) {
            final int suffixLength = propertyId.length() - Constants.XERCES_PROPERTY_PREFIX.length();
            
            if (suffixLength == Constants.DTD_SCANNER_PROPERTY.length() && 
                    propertyId.endsWith(Constants.DTD_SCANNER_PROPERTY)) {
                return;
            }
        }
        
        if (propertyId.startsWith(Constants.JAXP_PROPERTY_PREFIX)) {
            final int suffixLength = propertyId.length() - Constants.JAXP_PROPERTY_PREFIX.length();
            
            if (suffixLength == Constants.SCHEMA_SOURCE.length() && 
                    propertyId.endsWith(Constants.SCHEMA_SOURCE)) {
                return;
            }
        }
        
        //
        // Not recognized
        //
        
        super.checkProperty(propertyId);
        
    } // checkProperty(String)
    
    /**
     * Adds all of the component's recognized features and properties
     * to the list of default recognized features and properties, and
     * sets default values on the configuration for features and
     * properties which were previously absent from the configuration.
     *
     * @param component The component whose recognized features
     * and properties will be added to the configuration
     */
    private void addRecognizedParamsAndSetDefaults(XMLComponent component) {
        
        // register component's recognized features
        String[] recognizedFeatures = component.getRecognizedFeatures();
        addRecognizedFeatures(recognizedFeatures);
        
        // register component's recognized properties
        String[] recognizedProperties = component.getRecognizedProperties();
        addRecognizedProperties(recognizedProperties);

        // set default values
        if (recognizedFeatures != null) {
            for (int i = 0; i < recognizedFeatures.length; ++i) {
                String featureId = recognizedFeatures[i];
                Boolean state = component.getFeatureDefault(featureId);
                if (state != null) {
                    // Do not overwrite values already set on the configuration.
                    if (!fFeatures.containsKey(featureId)) {
                        fFeatures.put(featureId, state);
                        // For newly added components who recognize this feature
                        // but did not offer a default value, we need to make
                        // sure these components will get an opportunity to read
                        // the value before parsing begins.
                        fConfigUpdated = true;
                    }
                }
            }
        }
        if (recognizedProperties != null) {
            for (int i = 0; i < recognizedProperties.length; ++i) {
                String propertyId = recognizedProperties[i];
                Object value = component.getPropertyDefault(propertyId);
                if (value != null) {
                    // Do not overwrite values already set on the configuration.
                    if (!fProperties.containsKey(propertyId)) {
                        fProperties.put(propertyId, value);
                        // For newly added components who recognize this property
                        // but did not offer a default value, we need to make
                        // sure these components will get an opportunity to read
                        // the value before parsing begins.
                        fConfigUpdated = true;
                    }
                }
            }
        }
    }
    
    /**
     * Reset all XML 1.0 components before parsing
     */
    protected final void resetXML10() throws XNIException {
        // Reset XML 1.0 components
        fNamespaceScanner.reset(this);
        fDTDScanner.reset(this);
    } // resetXML10()
    
    /**
     * Reset all XML 1.1 components before parsing
     */
    protected final void resetXML11() throws XNIException {
        // Reset XML 1.1 components
        fXML11NSDocScanner.reset(this);
        fXML11DTDScanner.reset(this);
    } // resetXML11()
    
    //
    // other methods
    //
    
    /** */
    public void resetNodePool() {
        // REVISIT: to implement: introduce a node pool to reuse DTM nodes.
        //          reset this pool here.
    }
    
    private void initXML11Components() {
        if (!f11Initialized) {
            // create datatype factory
            fXML11DatatypeFactory = DTDDVFactory.getInstance(XML11_DATATYPE_VALIDATOR_FACTORY);

            // setup XML 1.1 DTD pipeline
            fXML11DTDScanner = new XML11DTDScannerImpl();
            addRecognizedParamsAndSetDefaults(fXML11DTDScanner);

            // setup XML 1.1. document pipeline - namespace aware
            fXML11NSDocScanner = new XML11NSDocumentScannerImpl();
            addRecognizedParamsAndSetDefaults(fXML11NSDocScanner);
                
            f11Initialized = true;
        }
    }
}
