Directory Structure

Flamigo projects follow an opinionated, domain-driven folder structure that promotes clean architecture and separation of concerns. This layout helps developers quickly locate and reason about different parts of the system, especially in larger codebases:

cmd/                     # Entry point of the application (main executable)

internal/
  api/                   # API strategy implementations
  
  domains/               # Core business logic organized by domain
    <domainName>/
      app/               # Application services and domain listeners
                         # Listens to events from other domains
                         # (package <domainName>_app)

      domain/            # Domain layer with entities, interfaces, value objects, and events
                         # (package <domainName>)

      infrastructure/    # Infrastructure layer with implementations for repositories, adapters, etc.
                         # (package <domainName>_infra)

  adapters/              # Adapters to the outside world, such as HTTP, WebSockets, or external APIs

This structure is designed to support modular development and enforce the boundaries between domain logic and infrastructure, making your codebase both testable and scalable.

Linking Code Together

The whole framework links everything together by using dependency injection. the pattern is the following: Different packages define an init.go file with a method like the following to handle dependency injection and initialize the package.

init.go

package api
func Init(inj injection.Container, db database.Database) error {
  // Does all the initialization
}

This can then be invoked through the injector:

container := injection.NewInjector()
container.Invoke(api.Init)

TIP

The injector can also inject itself, which allows nesting Init functions inside each other.

It is common to have many of these across an app, and they may call each other in a nested way.

e.g. in a small real world app this might be the structure of init functions calling each other:

main.go 
        -> api/init.go
                      -> api/users/init.go
                      -> api/messages/init.go
        -> domains/users/infrastructure/init.go
        -> domains/messages/infrastructure/init.go

        -> domains/users/app/init.go
        -> domains/users/messages/init.go

        -> adapters/websocket/init.go

WARNING

As already pointed out under Dependency Injection, only use this during startup and never during runtime of your app