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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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package com.sun.tools.internal.xjc.reader;

import java.util.StringTokenizer;

import com.sun.tools.internal.xjc.Options;

import org.xml.sax.Attributes;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;

This filter checks jaxb:extensionBindingPrefix and
pass/filter extension bindings.

This filter also remembers enabled extension namespaces
and filters out any extension namespaces that doesn't belong
to those. The net effect is that disabled customizations
will never pass through this filter.

Note that we can't just filter out all foreign namespaces,
as we need to use user-defined tags in documentations to generate javadoc.

The class needs to know the list of extension binding namespaces
that the RI recognizes.
To add new URI, modify the isSupportedExtension method.
Author:

    Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)/**
 * This filter checks jaxb:extensionBindingPrefix and
 * pass/filter extension bindings.
 *
 * <p>
 * This filter also remembers enabled extension namespaces
 * and filters out any extension namespaces that doesn't belong
 * to those. The net effect is that disabled customizations
 * will never pass through this filter.
 *
 * <p>
 * Note that we can't just filter out all foreign namespaces,
 * as we need to use user-defined tags in documentations to generate javadoc.
 *
 * <p>
 * The class needs to know the list of extension binding namespaces
 * that the RI recognizes.
 * To add new URI, modify the isSupportedExtension method.
 *
 * @author
 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
public final class ExtensionBindingChecker extends AbstractExtensionBindingChecker {

    
Number of the elements encountered. Used to detect the root element.
/**
     * Number of the elements encountered. Used to detect the root element.
     */
    private int count=0;

    public ExtensionBindingChecker(String schemaLanguage, Options options, ErrorHandler handler) {
        super(schemaLanguage, options, handler);
    }

    
Returns true if the elements with the given namespace URI
should be blocked by this filter.
/**
     * Returns true if the elements with the given namespace URI
     * should be blocked by this filter.
     */
    private boolean needsToBePruned( String uri ) {
        if( uri.equals(schemaLanguage) )
            return false;
        if( uri.equals(Const.JAXB_NSURI) )
            return false;
        if( enabledExtensions.contains(uri) )
            return false;

        // we don't need to prune something unless
        // the rest of the processor recognizes it as something special.
        // this allows us to send the documentation and other harmless
        // foreign XML fragments, which may be picked up as documents.
        return isRecognizableExtension(uri);
    }


    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
        count=0;
    }

    @Override
    public void startElement(String namespaceURI, String localName, String qName, Attributes atts)
        throws SAXException {

        if(!isCutting()) {
            String v = atts.getValue(Const.JAXB_NSURI,"extensionBindingPrefixes");
            if(v!=null) {
                if(count!=0)
                    // the binding attribute is allowed only at the root level.
                    error( Messages.ERR_UNEXPECTED_EXTENSION_BINDING_PREFIXES.format() );

                if(!allowExtensions)
                    error( Messages.ERR_VENDOR_EXTENSION_DISALLOWED_IN_STRICT_MODE.format() );

                // then remember the associated namespace URIs.
                StringTokenizer tokens = new StringTokenizer(v);
                while(tokens.hasMoreTokens()) {
                    String prefix = tokens.nextToken();
                    String uri = nsSupport.getURI(prefix);
                    if( uri==null )
                        // undeclared prefix
                        error( Messages.ERR_UNDECLARED_PREFIX.format(prefix) );
                    else
                        checkAndEnable(uri);
                }
            }

            if( needsToBePruned(namespaceURI) ) {
                // start pruning the tree. Call the super class method directly.
                if( isRecognizableExtension(namespaceURI) ) {
                    // but this is a supported customization.
                    // isn't the user forgetting @jaxb:extensionBindingPrefixes?
                    warning( Messages.ERR_SUPPORTED_EXTENSION_IGNORED.format(namespaceURI) );
                }
                startCutting();
            } else
                verifyTagName(namespaceURI, localName, qName);
        }

        count++;
        super.startElement(namespaceURI, localName, qName, atts);
    }
}