Intro

Why the Focus on the Domain?

Common Language

What have Users, Business Analysts and Developers in common?

Right, they should know the Domain that they are using or providing.

To have a common domain prevents that each team has its own domain model and speaks a (slightly) different language.

Vendor Independent

The Domain Model is specific to a Company and should not be coupled to a Software vendor or a BPMN-Provider in this case.

Specifies the Process

A Process, but also for example a User Task, can be described via its inputs and outputs, which must of course reflect your Domain.

So from the outside all you need to know, is how to interact with your process. And this how can we describe perfectly with domain objects.

Reusable

If for example you provide the domain objects for your processes, everyone can reuse them, when interacting with your processes or developing processes in the same domain.

Design

The design consists of three Layers:

1. Domain Specification

   Defines your Domain that is needed to run the Process and interact with it.

2. BPMN DSL

   Adds your Domain Model to concrete BPMN elements, like Process or User Task.

   

   DSL stays for Domain Specific Language.

3. Function DSLs

   Different DSLs that add the functionality. We have the following DSLs at the moment:

   • api: Create a documentation from your Domain Models.
   • simulation: Run integration- and/ or load Tests with your Domain Models.

   There are more, but only in an experimental state:

   • dmn: Create the configurations for the DMN Tester.
   • camunda: Generate some of your Process Specification.

Technology

• Process Specification

  This is standard Camunda BPMN XML.

• Domain Specification

  We describe the Domain with Scala 3. Here we use mainly:

  • Case Classes
  • Enums

  See FP Domain Modeling

• BPMN- and Function DSLs

  You can use a simple language to describe your BPMNs and Functionalities. Under the hood we use:

  Scala’s features for DSL design: curried functions, extension methods, symbolic method names and scripting capability. Another great such feature new to Scala 3 is the Context Function type.
  

  (from Context Function for DSL Design in Scala)

Getting Started

Just go through the pages:

1. Process & Domain Specification
2. BPMN DSL
3. Functionality DSLs