Workflow Engine: OSWorkflow

OSWorkflow Reference

OSWorkflow is now not maintenenced by provider. See more information from: 

Explain osworkflow basic concept and how to use osworkflow.

It is important to understand following concepts:

  1. Functions and conditions
  2. Result and unconditional result
  3. transientVars , property set and arguments
  4. some other basic os workflow concept.

Transient Var and Property Set

Business processes need to store bits of data during their lifetime or certain periods of time for working purposes. The data that stays alive only during the workflow instance execution is called transient data. Information stored across invocations is called persistent data.

Integrate OSWorkflow in Spring

We can find Workflow and its classes Configuration from:

  • osworkflow-spring.xml

We can find Workflow Store related persistence information from:

  • opensymphony.hbm.xml

OsWorkflow Source Code Analyze

Initialize Workflow

Here we can study the source code of com.opensymphony.workflow.AbstractWorkflow.initialize(*) to see what's happened behind workflow initialization:
public long initialize(String workflowName, int initialAction, Map inputs) throws InvalidRoleException, 
      InvalidInputException, WorkflowException {
        WorkflowDescriptor wf = getConfiguration().getWorkflow(workflowName); // #1

        WorkflowStore store = getPersistence();//- #2
        WorkflowEntry entry = store.createEntry(workflowName);// #2

        // start with a memory property set, but clone it after we have an ID
        PropertySet ps = store.getPropertySet(entry.getId()); // #3
        Map transientVars = new HashMap();

        if (inputs != null) {
            transientVars.putAll(inputs);
        }

        populateTransientMap(entry, transientVars, wf.getRegisters(), new Integer(initialAction), Collections.EMPTY_LIST, ps);

        if (!canInitialize(workflowName, initialAction, transientVars, ps)) {
            context.setRollbackOnly();
            throw new InvalidRoleException("You are restricted from initializing this workflow");
        }

        ActionDescriptor action = wf.getInitialAction(initialAction);

        try {
            transitionWorkflow(entry, Collections.EMPTY_LIST, store, wf, action, transientVars, inputs, ps);
        } catch (WorkflowException e) {
            context.setRollbackOnly();
            throw e;
        }

        long entryId = entry.getId();

        // now clone the memory PS to the real PS
        //PropertySetManager.clone(ps, store.getPropertySet(entryId));
        return entryId;
    }

#1: Workflow Engine will first call Configuration to get WorkflowDescriptor. Configuration will delegate the request to HibernateWorkflowFactory.getWorkflow(String:workflowName, Boolean:validate) .

#2:WorkflowEnginewillcreateanewEntryfortoberunworkflow.

#3: Initial a PropertySet associated to the Workflow.

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