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Decorators

This section covers decorators used to provide binding metadata.

provide​

Decorator used to set binding metadata to be loaded into the container.

warning

Like any other decorator, @provide has no effect on non loaded modules. Make sure to import the module where the decorated class is defined.

Example: providing class self binding​

You can use the @provide decorator to provide a class self binding by not passing any parameters.

@injectable()
@provide()
class Katana {
  public readonly damage: number = 10;
}

@injectable()
@provide()
class Ninja {
  constructor(
    @inject(Katana)
    public readonly katana: Katana,
  ) {}
}

Example: providing class service binding​

You can use the @provide decorator to provide a class service binding by passing the service identifier as a parameter.

@injectable()
@provide('Katana')
class Katana {
  public readonly damage: number = 10;
}

@injectable()
@provide('Ninja')
class Ninja {
  constructor(
    @inject(Katana)
    public readonly katana: Katana,
  ) {}
}

Example: providing class service binding with a custom binding constraint​

You can use the @provide decorator to provide a class service binding with a custom binding constraint by passing the service identifier and a bind action as parameters. The bind action receives the fluent syntax to add additional configuration such as scopes and constraints.

@injectable()
@provide('Katana', (bind: BindInWhenOnFluentSyntax<Katana>) => {
  bind.inSingletonScope().whenNamed('GoldenKatana');
})
class Katana {
  public readonly damage: number = 10;
}

Example: providing multiple bindings​

You can use the @provide decorator to provide multiple bindings by applying it multiple times.

@injectable()
@provide()
@provide('Katana')
class Katana {
  public readonly damage: number = 10;
}

@injectable()
@provide()
@provide('Ninja')
class Ninja {
  constructor(
    @inject(Katana)
    public readonly katana: Katana,
  ) {}
}