/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jbpm.graph.node;
import java.util.ArrayList;
import java.util.Collection;
import org.dom4j.Element;
import org.jbpm.JbpmException;
import org.jbpm.context.def.ContextDefinition;
import org.jbpm.context.exe.ContextInstance;
import org.jbpm.graph.def.Node;
import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.exe.Token;
import org.jbpm.jpdl.xml.JpdlXmlReader;
import org.jbpm.util.CollectionUtil;
/**
* is an unordered set of child nodeMap. the path of execution will be given to each node exactly
* once. the sequence of the child nodeMap will be determined at runtime. this implements the
* workflow pattern interleved parallel routing. If no script is supplied, the transition names will
* be sequenced in arbitrary order. If a script is provided, the variable transitionNames contains
* the available transition names. The returned value has to be one of those transitionNames.
* Instead of supplying a script, its also possible to subclass this class and override the
* selectTransition method.
*/
public class InterleaveStart extends Node {
private static final long serialVersionUID = 1L;
String variableName = "interleave-transition-names";
Interleaver interleaver = new DefaultInterleaver();
public interface Interleaver {
String selectNextTransition(Collection<String> transitionNames);
}
public class DefaultInterleaver implements Interleaver {
public String selectNextTransition(Collection<String> transitionNames) {
return transitionNames.iterator().next();
}
}
public InterleaveStart() {
}
public InterleaveStart(String name) {
super(name);
}
public void read(Element element, JpdlXmlReader jpdlReader) {
// TODO
// just making sure that the context definition is present
// because the interleave node needs the context instance at runtime
ProcessDefinition processDefinition = jpdlReader.getProcessDefinition();
if (processDefinition.getDefinition(ContextDefinition.class) == null) {
processDefinition.addDefinition(new ContextDefinition());
}
}
public void write(Element element) {
// TODO
}
public void execute(ExecutionContext executionContext) {
Token token = executionContext.getToken();
Collection<String> transitionNames = retrieveTransitionNames(token);
// if this is the first time we enter
if (transitionNames == null) {
// collect all leaving transition names
transitionNames = new ArrayList<String>(getTransitionNames(token));
}
// select one of the remaining transition names
String nextTransition = interleaver.selectNextTransition(transitionNames);
// remove it from the remaining transitions
transitionNames.remove(nextTransition);
// store the transition names
storeTransitionNames(transitionNames, token);
// pass the token over the selected transition
token.getNode().leave(executionContext, nextTransition);
}
protected Collection<String> getTransitionNames(Token token) {
Node node = token.getNode();
return node.getLeavingTransitionsMap().keySet();
}
protected void storeTransitionNames(Collection<String> transitionNames, Token token) {
ContextInstance ci = token.getProcessInstance().getContextInstance();
if (ci == null)
throw new JbpmException("an interleave start node requires the availability of a context");
ci.setVariable(variableName, transitionNames, token);
}
public Collection<String> retrieveTransitionNames(Token token) {
ContextInstance ci = token.getProcessInstance().getContextInstance();
Collection<?> collection = (Collection<?>) ci.getVariable(variableName, token);
return collection != null ? CollectionUtil.checkCollection(collection, String.class) : null;
}
public void removeTransitionNames(Token token) {
ContextInstance ci = token.getProcessInstance().getContextInstance();
ci.setVariable(variableName,null, token);
}
public Interleaver getInterleaver() {
return interleaver;
}
public void setInterleaver(Interleaver interleaver) {
this.interleaver = interleaver;
}
}