Dependency Injection (Binds)

Nidus uses a DI container (based on InjectorBr) to resolve dependencies within module scope.

Bind types

Binds are declared in a module Binds method using Bind<T> syntax (shortcut available in Nidus.Module).

• Bind<T>.Singleton: creates instance when module starts
• Bind<T>.SingletonLazy: creates the instance on first request
• Bind<T>.Factory: creates on demand
• Bind<T>.SingletonInterface<I>: exposes an interface resolved via GetInterface<I>

Example

unit NFe.Module;

interface

uses
  Nidus.Module;

type
  TNFeModule = class(TModule)
  public
    function Binds: TBinds; override;
  end;

implementation

uses
  NFe.Repository,
  NFe.Controller,
  NFe.Provider;

function TNFeModule.Binds: TBinds;
begin
  Result := [
    Bind<TRepositoryServer>.SingletonLazy,
    Bind<TControllerServer>.Singleton,
    Bind<TProviderORMBr>.Factory
  ];
end;

end.

caution

For a bind to be eligible for replacement/override, the target type must be declared correctly in Bind<T>.