/**
* Copyright 2010 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.jbpm.process.instance.impl;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.util.List;
import org.drools.base.mvel.MVELCompilationUnit;
import org.drools.base.mvel.MVELCompileable;
import org.drools.base.mvel.MVELDebugHandler;
import org.drools.definition.KnowledgePackage;
import org.drools.definitions.impl.KnowledgePackageImp;
import org.drools.impl.InternalKnowledgeBase;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.Package;
import org.drools.runtime.process.ProcessContext;
import org.drools.spi.GlobalResolver;
import org.mvel2.MVEL;
import org.mvel2.compiler.CompiledExpression;
import org.mvel2.debug.DebugTools;
import org.mvel2.integration.VariableResolverFactory;
import org.mvel2.integration.impl.SimpleValueResolver;
public class MVELReturnValueEvaluator
implements
ReturnValueEvaluator,
MVELCompileable,
Externalizable {
private static final long serialVersionUID = 510l;
private MVELCompilationUnit unit;
private String id;
private Serializable expr;
public MVELReturnValueEvaluator() {
}
public MVELReturnValueEvaluator(final MVELCompilationUnit unit,
final String id) {
this.unit = unit;
this.id = id;
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
id = in.readUTF();
unit = (MVELCompilationUnit) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeUTF( id );
out.writeObject( unit );
}
public void compile(MVELDialectRuntimeData data) {
expr = unit.getCompiledExpression( data );
}
public String getDialect() {
return this.id;
}
public Object evaluate(ProcessContext context) throws Exception {
int length = unit.getOtherIdentifiers().length;
Object[] vars = new Object[ length ];
if (unit.getOtherIdentifiers() != null) {
for (int i = 0; i < length; i++ ) {
vars[i] = context.getVariable( unit.getOtherIdentifiers()[i] );
}
}
VariableResolverFactory factory = unit.getFactory( context, null, null, null, vars, null, (GlobalResolver) context.getKnowledgeRuntime().getGlobals() );
// do we have any functions for this namespace?
KnowledgePackage pkg = context.getKnowledgeRuntime().getKnowledgeBase().getKnowledgePackage( "MAIN" );
if ( pkg != null && pkg instanceof KnowledgePackageImp) {
MVELDialectRuntimeData data = ( MVELDialectRuntimeData ) ((KnowledgePackageImp) pkg).pkg.getDialectRuntimeRegistry().getDialectData( id );
factory.setNextFactory( data.getFunctionFactory() );
}
Object value = MVEL.executeExpression( this.expr,
null,
factory );
if ( !(value instanceof Boolean) ) {
throw new RuntimeException( "Constraints must return boolean values: " +
unit.getExpression() + " returns " + value +
(value == null? "" : " (type=" + value.getClass()));
}
return ((Boolean) value).booleanValue();
}
public Serializable getCompExpr() {
return expr;
}
public String toString() {
return this.unit.getExpression();
}
}