package org.drools.examples.conway.rules.dsl;
import org.drools.examples.conway.Cell;
import org.drools.rule.Declaration;
import org.drools.rule.InvalidRuleException;
import org.drools.rule.Rule;
import org.drools.semantics.base.ClassObjectType;
import org.drools.smf.Configuration;
import org.drools.smf.ConsequenceFactory;
import org.drools.smf.FactoryException;
import org.drools.spi.Consequence;
import org.drools.spi.RuleBaseContext;
/**
* @author <a href="mailto:brown_j@ociweb.com">Jeff Brown</a>
* @version $Id: ConwayConsequenceFactory.java,v 1.2 2005/05/16 23:31:19 brownj Exp $
*/
public class ConwayConsequenceFactory
implements
ConsequenceFactory
{
public Consequence newConsequence(Rule rule,
RuleBaseContext context,
Configuration config) throws FactoryException
{
Configuration childConfig = null;
Configuration[] configurations = config.getChildren();
Consequence consequence = null;
final String cellName = config.getAttribute( "cellName" );
final Declaration cellDeclaration = getDeclaration( rule,
Cell.class,
cellName );
for ( int i = 0; i < configurations.length; i++ )
{
childConfig = configurations[i];
if ( childConfig.getName().equals( "giveBirthToCell" ) )
{
consequence = new GiveBirthConsequence( cellDeclaration );
} else if ( childConfig.getName().equals( "killCell" ) )
{
consequence = new KillCellConsequence( cellDeclaration );
}
}
return consequence;
}
private Declaration getDeclaration(Rule rule,
Class clazz,
String identifier) throws FactoryException
{
Declaration declaration = rule.getParameterDeclaration( identifier );
if ( declaration == null )
{
ClassObjectType type = new ClassObjectType( clazz );
try
{
declaration = rule.addParameterDeclaration( identifier,
type );
}
catch ( InvalidRuleException e )
{
final FactoryException factoryException = new FactoryException( "Error occurred establishing parameter." );
factoryException.initCause( e );
throw factoryException;
}
}
return declaration;
}
}