https://github.com/fraktalio/fmodel-demos

Functional Domain Modeling - Demos - https://fraktalio.com/fmodel/
https://github.com/fraktalio/fmodel-demos

architecture arrow-kt ddd demo-app event-modeling event-sourcing functional-programming kotlin modeling oop-principles reactive reactive-programming

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Functional Domain Modeling - Demos - https://fraktalio.com/fmodel/

• Host: GitHub
• URL: https://github.com/fraktalio/fmodel-demos
• Owner: fraktalio
• License: other
• Created: 2021-04-18T13:21:15.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2023-08-25T07:18:56.000Z (over 1 year ago)
• Last Synced: 2024-08-03T18:21:04.978Z (5 months ago)
• Topics: architecture, arrow-kt, ddd, demo-app, event-modeling, event-sourcing, functional-programming, kotlin, modeling, oop-principles, reactive, reactive-programming
• Language: Kotlin
• Homepage:
• Size: 11.6 MB
• Stars: 49
• Watchers: 6
• Forks: 7
• Open Issues: 7
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

Awesome Lists containing this project

• awesome-eventmodeling - fmodel | Restaurant System

README

        
# Functional domain modeling - Examples

The word `domain` here means the area of interest in the business. When you are developing an `information system` to

automate activities of that business, you’re modeling the business. The abstractions that you design, the behaviors that

you implement, and the UI interactions that you build all reflect the business — *together they constitute the `model`

of the domain*.

## f(model)

These examples are demonstrating the usage of the [fmodel](https://fraktalio.com/fmodel)

library.

Library is written in [Kotlin](https://kotlinlang.org/) programing language by practicing functional style. It is a

small library constructed out of generic data types that can be used to effectively model any stateful information

system.

It is truly decoupling the pure declaration of our program logic from the runtime. And therefore, the runtime has the

chance to see the big picture of our program and decide how to run and optimize it.

## Examples

To demonstrate that `pure declaration of our program logic` is separated from the runtime target and infrastructure, we

are going to

practice [onion architecture / ports and adapters](https://blog.ploeh.dk/2013/12/03/layers-onions-ports-adapters-its-all-the-same/)

in all examples.

![onion architecture image](.assets/onion.png)

The arrows in the image are showing the direction of the dependency. Notice that all dependencies point inwards, and

that Domain is not depending on anybody or anything.

### Restaurant management system

Restaurant management system is:

- managing restaurant menus and other information including location and opening hours

- managing the preparation of orders at a restaurant kitchen

![restaurant management - event model](.assets/event-model.jpg)

We are going to run our [**unique** core domain](domain) logic in different ways, by implementing

different [application](application) and/or `persistence` layers:

| Type | Description | Technology | Scenario | Domain | Application | Adapter |

| --- | --- | --- | --- | --- | --- | --- |

| [State stored information system](application/state-stored-system1) | Restaurant management | Kotlin, Arrow, Reactive Spring Boot, R2DBC | combined aggregate scenario - monolith aggregate | `fmodel domain` | `fmodel application` | `spring` |

| [Event-sourced information system](application/event-sourced-system1) | Restaurant management| Kotlin, Arrow, Reactive Spring Boot, [Axon Framework](https://axoniq.io/product-overview/axon-framework) on infra layer, and [Axon Server](https://axoniq.io/product-overview/axon-server) | combined aggregate scenario - monolith aggregate | `fmodel domain` | `fmodel application` | `axon`, `spring` |

| [Event-sourced information system - distributed](application/event-sourced-system2) | Restaurant management| Kotlin, Arrow, Reactive Spring Boot, [Axon Framework](https://axoniq.io/product-overview/axon-framework) on infra layer, and [Axon Server](https://axoniq.io/product-overview/axon-server) | distributed aggregate(s) | `fmodel domain` | `fmodel application` | `axon`, `spring` |

| [Event-sourced information system - distributed](application/event-sourced-system3) | Restaurant management| Kotlin, Arrow, Reactive Spring Boot, [Axon Framework](https://axoniq.io/product-overview/axon-framework) on application layer, and [Axon Server](https://axoniq.io/product-overview/axon-server) | distributed aggregate(s) | `fmodel domain` | `axon` | `axon`, `spring` |

## References and further reading

- [https://fraktalio.com/fmodel/](https://fraktalio.com/fmodel/)

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Created with :heart: by [Fraktalio](https://fraktalio.com/)