/*
* Copyright 2006 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.
*/
package org.drools.rule.builder.dialect.mvel;
import java.util.Map;
import org.drools.base.ClassObjectType;
import org.drools.base.mvel.MVELCompilationUnit;
import org.drools.base.mvel.MVELPredicateExpression;
import org.drools.compiler.AnalysisResult;
import org.drools.compiler.BoundIdentifiers;
import org.drools.compiler.DescrBuildError;
import org.drools.lang.descr.PredicateDescr;
import org.drools.rule.Declaration;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.Pattern;
import org.drools.rule.PredicateConstraint;
import org.drools.rule.builder.PredicateBuilder;
import org.drools.rule.builder.RuleBuildContext;
import org.drools.spi.KnowledgeHelper;
import static org.drools.rule.builder.dialect.DialectUtil.copyErrorLocation;
public class MVELPredicateBuilder
implements
PredicateBuilder {
public void build( final RuleBuildContext context,
final BoundIdentifiers usedIdentifiers,
final Declaration[] previousDeclarations,
final Declaration[] localDeclarations,
final PredicateConstraint predicate,
final PredicateDescr predicateDescr,
final AnalysisResult analysis ) {
boolean typesafe = context.isTypesafe();
if (typesafe && analysis instanceof MVELAnalysisResult) {
Class<?> returnClass = ((MVELAnalysisResult)analysis).getReturnType();
if (returnClass != Boolean.class && returnClass != Boolean.TYPE) {
context.addError( new DescrBuildError( context.getParentDescr(),
predicateDescr,
null,
"Predicate '" + predicateDescr.getContent() + "' must be a Boolean expression\n" + predicateDescr.positionAsString() ) );
}
}
MVELDialect dialect = (MVELDialect) context.getDialect( context.getDialect().getId() );
try {
Map<String, Class< ? >> declIds = context.getDeclarationResolver().getDeclarationClasses( context.getRule() );
Pattern p = (Pattern) context.getBuildStack().peek();
if ( p.getObjectType() instanceof ClassObjectType ) {
declIds.put( "this",
((ClassObjectType) p.getObjectType()).getClassType() );
}
MVELCompilationUnit unit = dialect.getMVELCompilationUnit((String) predicateDescr.getContent(),
analysis,
previousDeclarations,
localDeclarations,
null,
context,
"drools",
KnowledgeHelper.class,
false );
MVELPredicateExpression expr = new MVELPredicateExpression( unit,
context.getDialect().getId() );
predicate.setPredicateExpression( expr );
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( "mvel" );
data.addCompileable( predicate,
expr );
expr.compile( data );
} catch ( final Exception e ) {
copyErrorLocation(e, predicateDescr);
context.addError( new DescrBuildError( context.getParentDescr(),
predicateDescr,
e,
"Unable to build expression for 'inline-eval' : " + e.getMessage() + "'" + predicateDescr.getContent() + "'\n" + e.getMessage() ) );
} finally {
context.setTypesafe( typesafe );
}
}
}