abstract class Radbas::Container

• Radbas::Container
• Reference
• Object

Overview

A small dependency injection container, wired at compile time.

Extend Radbas::Container and register services in the class body:

class MyContainer < Radbas::Container
  # resolve every class inside these namespaces automatically
  autowire(MyApp, CustomNamespace)

  # register all concrete subclasses of an abstract class
  register_subclasses(MyApp::Handler, public: true)

  # register a single service, constructor dependencies are injected
  register(DependencyService)

  # set constructor arguments explicitly, `get` resolves other entries
  register(MyService, params: {dep: get(DependencyService), name: "my"})

  # or build the service yourself with a call or proc
  register(OtherService, factory: -> { OtherService.new(get(DependencyService)) })

  # public entries can be fetched from outside the container
  register(MyApplication, public: true)
end

MyContainer.new.get(MyApplication).run

Registration macros:

• register(Type, params: NamedTuple?, factory: Call | Proc?, public: Bool = false) registers Type. params and factory are mutually exclusive, abstract types need a factory.
• autowire(*namespaces) lets dependencies inside the given namespaces be registered on first use.
• register_subclasses(AbstractType, params: NamedTuple?, public: Bool = false) registers every concrete, non-generic subclass of AbstractType. Explicit register calls take precedence.

Services are created lazily on the first #get and then cached, so every container instance holds exactly one instance per service. Configuration errors are reported at compile time.

Defined in:

radbas-container.cr

Constant Summary

VERSION = "1.0.0"

Instance Method Summary

• #get(id : T.class) forall T

  Returns the container itself when id is the container class or one of its ancestors.

Instance Method Detail