package org.drools.xml.rules;
/*
* Copyright 2005 JBoss Inc
*
* 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.
*/
import java.util.HashSet;
import org.drools.lang.descr.AndDescr;
import org.drools.lang.descr.ConditionalElementDescr;
import org.drools.lang.descr.EvalDescr;
import org.drools.lang.descr.ExistsDescr;
import org.drools.lang.descr.ForallDescr;
import org.drools.lang.descr.NotDescr;
import org.drools.lang.descr.OrDescr;
import org.drools.lang.descr.PatternDescr;
import org.drools.xml.BaseAbstractHandler;
import org.drools.xml.ExtensibleXmlParser;
import org.drools.xml.Handler;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
/**
* @author mproctor
*
* TODO To change the template for this generated type comment go to Window -
* Preferences - Java - Code Style - Code Templates
*/
public class ExistsHandler extends BaseAbstractHandler
implements
Handler {
public ExistsHandler() {
if ( (this.validParents == null) && (this.validPeers == null) ) {
this.validParents = new HashSet();
this.validParents.add( AndDescr.class );
this.validParents.add( OrDescr.class );
this.validParents.add( NotDescr.class );
this.validPeers = new HashSet();
this.validPeers.add( null );
this.validPeers.add( AndDescr.class );
this.validPeers.add( OrDescr.class );
this.validPeers.add( NotDescr.class );
this.validPeers.add( ExistsDescr.class );
this.validPeers.add( EvalDescr.class );
this.validPeers.add( PatternDescr.class );
this.validPeers.add( ForallDescr.class );
this.allowNesting = true;
}
}
public Object start(final String uri,
final String localName,
final Attributes attrs,
final ExtensibleXmlParser parser) throws SAXException {
parser.startElementBuilder( localName,
attrs );
final ExistsDescr existsDescr = new ExistsDescr();
return existsDescr;
}
public Object end(final String uri,
final String localName,
final ExtensibleXmlParser parser) throws SAXException {
final Element element = parser.endElementBuilder();
final ExistsDescr existsDescr = (ExistsDescr) parser.getCurrent();
if ( (existsDescr.getDescrs().size() != 1) && (existsDescr.getDescrs().get( 0 ).getClass() != PatternDescr.class) ) {
throw new SAXParseException( "<exists> can only have a single <pattern...> as a child element",
parser.getLocator() );
}
final ConditionalElementDescr parentDescr = (ConditionalElementDescr) parser.getParent();
parentDescr.addDescr( existsDescr );
return existsDescr;
}
public Class generateNodeFor() {
return ExistsDescr.class;
}
}