Example processes implemented with rbpl

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Example 1 - Simplified email confirmation process

The scenario is a (very much) simplified process for confirming a user's email address, e.g. as part of a self-registration process.

Requirements

• Start the process with the email address to confirm
• Send an email to the provided address including a confirmation link
• Wait for a configurable amount of time for the confirmation link to be invoked
• Signal successful and unsuccessful (timeout) completion of the process

BPMN process model

Code examples

The main process model

#!scala
class EmailConfirmationProcess(val ctx: ProcessContext, val initializer: Initializer[EmailConfirmationProcess.StartData])
  extends BaseProcess(Initializer[EmailAddress](EmailConfirmationProcess.SendConfirmationEmailTaskName, initializer.payload.emailAddress) :: HNil, Some(initializer)) {

  import AndThenAPI._
  import EmailConfirmationProcess._

  def predicateArgument: Any = None

  def receiveRecover: Receive = Actor.emptyBehavior

  def receiveCommand: Receive = {

    case r: SendConfirmationEmailTask.EmailSent =>
      persistAndHandleResult(r) { res =>
        log.info("SendConfirmationEmailTask - result: {}", res)
      } andThen (
        StopCurrentTask(),
        StartNewTask(
          "confirmation email sent",
          Initializer(ExpectConfimationLinkClickedTaskName, r.token)),
          StartTimer(ConfirmationTimerID, initializer.payload.awaitDuration))

    case r: ExpectConfimationLinkClickedTask.LinkClicked =>
      persistAndHandleResult(r) { res =>
        log.info("PROCESS SUCESSFUL: ExpectConfimationLinkClickedTask - result: {}", res)
      } andThen (
        StopCurrentTask(),
        StopTimer(EmailConfirmationProcess.ConfirmationTimerID),
        StopProcess())

    case r @ TimerTask.TimerExpired(`ConfirmationTimerID`, _, _) =>
      persistAndHandleResult(r) { res =>
        log.info("PROCESS FAILURE: TimerTask.TimerExpired - result: {}", res)
      } andThen (
        StopTask(ExpectConfimationLinkClickedTaskName),
        StopTimer(EmailConfirmationProcess.ConfirmationTimerID),
        StopProcess())
  }
}

Resulting runtime diagram

rbpl-core contains a utility for dumping the current state of the process to a DOT-based diagram. With the provided HTML wrapper can the state directly be viewed in a browser.

Process state after start

Happy flow without timer expiration

Exceptional flow with timer expiration

Simplifications

• Print the email on the console rather then sending a real email ;)
• Print the successful/unsuccessful result also to the console ... an proper business event will be added later

Example 2 - Simple CMMN case with multiple user tasks

The scenario is a simplified process for collecting various aspects of data from a user. It is modelled using a CMMN case and human tasks and implemented using the corresponding semantical representations from rbpl-core.

Requirements

• Start the process and the CMMN case as its initial (and currently only) task.
• Let the user work on the various human tasks.
• Visualise invalid data (mandatory fields not provided, illegal values)
• Conditionally enable "Provide Legal Guardian" human task if age is below legal age, use a business rule for this.
• Enable a "completion" button if the milestone of the case is reached.

CMMN case model

### BPMN process model