package org.drools.compiler.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; } }