package org.drools.rule.builder;
/*
* 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 org.drools.RuntimeDroolsException;
import org.drools.base.SalienceInteger;
import org.drools.lang.descr.QueryDescr;
import org.drools.lang.descr.RuleDescr;
import org.drools.rule.GroupElement;
import org.drools.rule.Pattern;
import org.drools.spi.Salience;
/**
* This builds the rule structure from an AST.
* Generates semantic code where necessary if semantics are used.
* This is an internal API.
*/
public class RuleBuilder {
// Constructor
public RuleBuilder() {
}
/**
* Build the give rule into the
* @param pkg
* @param ruleDescr
* @return
*/
public void build(final RuleBuildContext context) {
RuleDescr ruleDescr = context.getRuleDescr();
final RuleConditionBuilder builder = (RuleConditionBuilder) context.getDialect().getBuilder( ruleDescr.getLhs().getClass() );
if ( builder != null ) {
Pattern prefixPattern = null;
if ( context.getRuleDescr() instanceof QueryDescr ) {
prefixPattern = context.getDialect().getQueryBuilder().build( context, ( QueryDescr ) context.getRuleDescr() );
}
final GroupElement ce = (GroupElement) builder.build( context,
ruleDescr.getLhs(),
prefixPattern );
context.getRule().setLhs( ce );
} else {
throw new RuntimeDroolsException( "BUG: builder not found for descriptor class " + ruleDescr.getLhs().getClass() );
}
// Build the consequence and generate it's invoker/s
// generate the main rule from the previously generated s.
if ( !(ruleDescr instanceof QueryDescr) ) {
// do not build the consequence if we have a query
context.getDialect().getConsequenceBuilder().build( context );
}
String salienceText = context.getRuleDescr().getSalience();
try {
// First see if its an Integer
if ( salienceText != null && !salienceText.equals( "" )) {
Salience salience = new SalienceInteger( Integer.parseInt( salienceText ) );
context.getRule().setSalience( salience );
}
} catch (Exception e) {
// It wasn't an integer, so build as an expression
context.getDialect().getSalienceBuilder().build( context );
}
RuleClassBuilder classBuilder = context.getDialect().getRuleClassBuilder();
if ( classBuilder != null ) {
classBuilder.buildRule( context );
}
}
}