DDD example in Ruby on Rails

This is a PoC application for implementing elements of Domain-Driven Design inside of a plain Ruby on Rails application.

THIS IS NOT PRODUCTION-LEVEL CODE. Its purpose is to serve as a validation of ideas and a discussion starting point.

Identified Subdomains and implemented Bounded Contexts

DragonHunt

Our company organises raids on dragons. But we need to assemble the parties first

CooperationNegotiation

Before a party is assembled, its leader needs to negotiate a contract. The contract signature is the defining moment for the party to be assembled.

Implemented scenario, joining two contexts

It implements a simple scenario (using ubiquitous languages for each of the domains):

• start negotiation by preparing a draft contract
• modify text of the contract to satisfy the client and the company
• the contract, in its final text form, needs to be signed by the client
• the contract, in its final text form, needs to be signed by the company
• when both sides sign the contract, it cannot be modified further
• signed contracts can be listed, including the text of contract and the time it has been signed
• when the contract is signed by both sides, a party is assembled in the DragonHunt context

Used DDD features

• contexts defined as modules inside of app/modules/ folder
• layers defined in each modules within application|domain|infrastructure folders
• repositories put into infrastructure layer
• persistance models put into infrastructure layer and translated into/out of domain models using repositories
• application services for each possible action within cooperation_negotiation context
• domain objects defined as POROs
• domain events defined as POROs
• domain events handled synchronously and used for cross-context communication
• factory methods defined on domain objects
• read models

Installation

rails db:create
rails db:migrate

rails db:seed

Reply all test scenarios with

rails db:seed:replant

Testing

The project uses Rspec as its testing framework. Run

rspec

to run all tests.

For continues testing during development you may use Guard with

guard

Future plans

• I'm thinking about adding some controllers and frontend to show that it can operate as a normal application.

Enjoy

Please let me know if you see anything you like, don't like or think can be done better