How to actually run process defined by Process API?

[espinosa_cz]

Manual chapter 5.1.3. Defining Processes Using the Process API is an exciting reading cut short. There is no hint how to run just defined process, how to add the process to Knowledge API.

I rummaged forums and mail list I found this two approaches, both works me, but both have issues.

Way 1 – casting to inner implementations

Casting KnowledgeBase and RulesBase to their particular implementations. This does no good to design. What is the point to have all nice and tidy interfaces like KnowledgeBuilder, KnowledgeBase, KnowledgeSession, when you have to cast to their particular impelementations in one crucial step.

Code snipplet:

RuleFlowProcessFactory factory = RuleFlowProcessFactory.createProcess("org.jbpm.HelloWorld");
factory.name("HelloWorldProcess").packageName("org.jbpm").startNode(1).... //finish definition
// add process definition to KnowledgeBase
RuleFlowProcess processDef1 = factory.validate().getProcess();
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
KnowledgeBase kbase = kbuilder.newKnowledgeBase();
((AbstractRuleBase)((InternalKnowledgeBase)kbase).getRuleBase()).addProcess(processDef1);
// run the process
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
ksession.startProcess("org.jbpm.HelloWorld");

Way 2 -  XmlBPMNProcessDumper

Using XmlBPMNProcessDumper is better on design side but (unnecessary) subsequent marshalling and unmarshalling making it not very effective variant.

Code snipplet:

RuleFlowProcessFactory factory = RuleFlowProcessFactory.createProcess("org.jbpm.process");
factory.name("My process").packageName("org.jbpm").startNode(1).... //finish definition
// add process definition to KnowledgeBuilder
RuleFlowProcess process = factory.validate().getProcess();
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(
 ResourceFactory.newByteArrayResource(
 XmlBPMNProcessDumper.INSTANCE.dump(process).getBytes()),
 ResourceType.BPMN2);
KnowledgeBase kbase = kbuilder.newKnowledgeBase();
// run the process
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
ksession.startProcess("org.jbpm.process");

Source: https://community.jboss.org/message/644606

Is there another, official, better way?

Whatever way, please amend the documentation and include some.

Underline notes

I also checked original Drools Flow documentation - 4.1.3. Defining Processes Using the Process API. It contains 3 examples how to define process, an abundance compared to jBPM manual, but any hint how to add it to KnowledgeBase and run it.

In the jBPM chapter – 5.1.3. - RuleFlowProcessFactory, creating RuleFlowProcess. All of sudden, from jBPM API back to Drools Flow API. Is this area of jBPM under development? Is this going to change? Covered by jBPM only APIs?