Skip to main content

Quickstart

This guide walks you through a minimal Nidus application in five steps.

1. Add the uses clause​

uses
  Nidus,
  Nidus.Module,      // TModule base class
  Nidus.Inject;      // initialises GNidusInject (include in .dpr)

Including Nidus.Inject in the project's .dpr (or any unit that loads before GetNidus is called) runs the initialization section, which creates the internal DI container.

2. Define a module​

type
  [Module]
  TUserModule = class(TModule)
  public
    procedure Configure(const ABuilder: IModuleBuilder); override;
  end;

procedure TUserModule.Configure(const ABuilder: IModuleBuilder);
begin
  ABuilder
    .AddProvider(TBind<TUserService>.Singleton)
    .Export(TUserService);
end;

3. Define a DTO with validation decorators​

uses
  Nidus.Decorator.IsEmail,
  Nidus.Decorator.IsNotEmpty,
  Nidus.Decorator.IsStrongPassword;

type
  TCreateUserDto = class
  private
    FName: string;
    FEmail: string;
    FPassword: string;
  public
    [IsNotEmpty('Name is required!')]
    property Name: string read FName write FName;

    [IsEmail('Invalid email address!')]
    property Email: string read FEmail write FEmail;

    [IsStrongPassword('Password is too weak!')]
    property Password: string read FPassword write FPassword;
  end;

4. Bootstrap the application​

var
  LApp: TNidus;
begin
  LApp := GetNidus;
  try
    LApp
      .UseListener(TMyLogger.Log)           // structured log callback
      .UsePipes(TValidationPipe.Create)      // global RTTI validation
      .UseCache(TMemoryCache.Create)         // module-level cache
      .UsePools<TMyHeavyResource>(128)       // object pool, max 128 items
      .Start(TAppModule.Create);             // boot the root module

    // Resolve a service by type
    var LUserService := LApp.Get<TUserService>;
    LUserService.Register('Isaque Pinheiro', 'isaquesp@gmail.com');
  finally
    LApp.Finalize;
  end;
end;

5. Integrate with Horse (HTTP)​

uses
  Horse,
  Nidus.Driver.Horse;

begin
  THorse
    .Use(Nidus_Horse(TAppModule.Create))   // boots Nidus + returns middleware
    .Get('/users', ...)
    .Listen(9000);
end;

Nidus_Horse(TAppModule) calls GetNidus.Start(AAppModule) internally and returns the Middleware callback that Horse executes on every request.

Next steps​