/**
* 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.drools.workflow.instance.node;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import org.drools.definition.process.Node;
import org.drools.process.core.context.variable.VariableScope;
import org.drools.process.instance.context.variable.VariableScopeInstance;
import org.drools.workflow.core.node.ForEachNode;
import org.drools.workflow.core.node.ForEachNode.ForEachJoinNode;
import org.drools.workflow.core.node.ForEachNode.ForEachSplitNode;
import org.drools.workflow.instance.NodeInstance;
import org.drools.workflow.instance.NodeInstanceContainer;
import org.drools.workflow.instance.impl.NodeInstanceImpl;
import org.drools.workflow.instance.impl.NodeInstanceResolverFactory;
import org.mvel2.MVEL;
/**
* Runtime counterpart of a for each node.
*
* @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>
*/
public class ForEachNodeInstance extends CompositeNodeInstance {
private static final long serialVersionUID = 510l;
public ForEachNode getForEachNode() {
return (ForEachNode) getNode();
}
public NodeInstance getNodeInstance(final Node node) {
// TODO do this cleaner for split / join of for each?
if (node instanceof ForEachSplitNode) {
ForEachSplitNodeInstance nodeInstance = new ForEachSplitNodeInstance();
nodeInstance.setNodeId(node.getId());
nodeInstance.setNodeInstanceContainer(this);
nodeInstance.setProcessInstance(getProcessInstance());
return nodeInstance;
} else if (node instanceof ForEachJoinNode) {
ForEachJoinNodeInstance nodeInstance = (ForEachJoinNodeInstance)
getFirstNodeInstance(node.getId());
if (nodeInstance == null) {
nodeInstance = new ForEachJoinNodeInstance();
nodeInstance.setNodeId(node.getId());
nodeInstance.setNodeInstanceContainer(this);
nodeInstance.setProcessInstance(getProcessInstance());
}
return nodeInstance;
}
return super.getNodeInstance(node);
}
public class ForEachSplitNodeInstance extends NodeInstanceImpl {
private static final long serialVersionUID = 510l;
public ForEachSplitNode getForEachSplitNode() {
return (ForEachSplitNode) getNode();
}
public void internalTrigger(org.drools.runtime.process.NodeInstance from, String type) {
String collectionExpression = getForEachNode().getCollectionExpression();
Collection<?> collection = evaluateCollectionExpression(collectionExpression);
((NodeInstanceContainer) getNodeInstanceContainer()).removeNodeInstance(this);
if (collection.isEmpty()) {
ForEachNodeInstance.this.triggerCompleted(org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE, true);
} else {
List<NodeInstance> nodeInstances = new ArrayList<NodeInstance>();
for (Object o: collection) {
String variableName = getForEachNode().getVariableName();
CompositeNodeInstance nodeInstance = (CompositeNodeInstance)
((NodeInstanceContainer) getNodeInstanceContainer()).getNodeInstance(getForEachSplitNode().getTo().getTo());
VariableScopeInstance variableScopeInstance = (VariableScopeInstance)
nodeInstance.resolveContextInstance(VariableScope.VARIABLE_SCOPE, variableName);
variableScopeInstance.setVariable(variableName, o);
nodeInstances.add(nodeInstance);
}
for (NodeInstance nodeInstance: nodeInstances) {
((org.drools.workflow.instance.NodeInstance) nodeInstance).trigger(this, getForEachSplitNode().getTo().getToType());
}
if (!getForEachNode().isWaitForCompletion()) {
ForEachNodeInstance.this.triggerCompleted(org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE, false);
}
}
}
private Collection<?> evaluateCollectionExpression(String collectionExpression) {
// TODO: should evaluate this expression using MVEL
Object collection = null;
VariableScopeInstance variableScopeInstance = (VariableScopeInstance)
resolveContextInstance(VariableScope.VARIABLE_SCOPE, collectionExpression);
if (variableScopeInstance != null) {
collection = variableScopeInstance.getVariable(collectionExpression);
} else {
try {
collection = MVEL.eval(collectionExpression, new NodeInstanceResolverFactory(this));
} catch (Throwable t) {
throw new IllegalArgumentException(
"Could not find collection " + collectionExpression);
}
}
if (collection == null) {
return Collections.EMPTY_LIST;
}
if (collection instanceof Collection<?>) {
return (Collection<?>) collection;
}
if (collection.getClass().isArray() ) {
List<Object> list = new ArrayList<Object>();
for (Object o: (Object[]) collection) {
list.add(o);
}
return list;
}
throw new IllegalArgumentException(
"Unexpected collection type: " + collection.getClass());
}
}
public class ForEachJoinNodeInstance extends NodeInstanceImpl {
private static final long serialVersionUID = 510l;
public ForEachJoinNode getForEachJoinNode() {
return (ForEachJoinNode) getNode();
}
public void internalTrigger(org.drools.runtime.process.NodeInstance from, String type) {
if (getNodeInstanceContainer().getNodeInstances().size() == 1) {
((NodeInstanceContainer) getNodeInstanceContainer()).removeNodeInstance(this);
if (getForEachNode().isWaitForCompletion()) {
triggerConnection(getForEachJoinNode().getTo());
}
}
}
}
}