Stardust/Knowledge Base/API/A first Look at the Stardust API

Introduction 

This article gives you first taste of Eclipse Process Manager (EPM) API. In this context, the EPM API is also refered as EPM services. The aim of this article is to explain the process of gaining an access to EPM services and give an overview of available services. We assume that you have already installed EPM modeler and have EPM runtime environment setup with simple process model deployed in it. If you haven't done this, please follow this documentation <link to come soon>.

Once you have EPM up and running with some process model or models deployed in it, you can start interacting with it via its exposed API. Normally, you will access the EPM services (API) via various different ways like as local spring services, spring remoting, or over WS API depending on your deployment setup. 

 

Establishing Connection with Runtime Environment

You will use the appropriate service factory to authenticate and establish connection with EPM runtime environment. We will see in detail how we use different service factories in a separate article. Assuming you authenticate and establish connection with EPM runtime, you can get a reference to EPM services via this initialized service factory.

You can initialize the service factory as simple as this;

ServiceFactory sf = ServiceFactoryLocator.get(user, pwd, properties);

EPM Services

Once you have initialized service factory, you can get access to the services offered by EPM. The reminder of this section gives overview of core services and some of their operations.

Workflow Service

The Workflow Service provides all functionality for workflow operations in an EPM runtime environment.
This includes:
* starting and aborting process instances,
* activating, completing, suspending and aborting activities,
* binding and unbinding event handlers,
* delegating activities, and
* accessing workflow data.

For example, you can get the workflow service from service factory and execute the startProcess() like this;

WorkflowService wfs = sf.getWorkflowService();
workflowService.startPrcoess("LeaveApplicationProcess", inputData, true);

Where, the parameters are;
       param1: process ID of the process which you want to start,
       param2: input data required to the process in the form of java.util.Map<String, ?>, and
       param3: flag to indicate if process should execute synchronously or asynchronously

Administration Service

This service provides administration services for the EPM runtime environment. An administration service always operates against an audit trail database. The administration service requires that the user performing tasks (in this case, the user used to initialize the service factory) has been assigned to the predefined role Administrator.

The functionality of this service includes the following tasks:

     * manage the workflow models (deploy, modify or delete)
     * recover the runtime environment or single workflow objects
     * terminate running process instances
     * manage the life cycle of daemons

 User Service

The User Service provides functionality for operating on EPM runtime users.

The operations includes:

   *creating, modifying and invalidating users, and
   * accessing user data.

Query Service

The Query Service provides services quering EPM runtime environment.  A Query service always operates against an audit trail database.

The functionality includes the following tasks:

   *retrieve or counts elements in the audit trail (users, process instance, activity instances or log events)
   * retrieve deployed models from the audit trails
   * retrieve participants from the models