vorarbeiter

A simple service container

1. Create some services:

interface Car {
  getDriverName(): string;
}

class CarImpl implements Car {
  constructor(private readonly driver: Driver) {}
  getDriverName() {
    return this.driver.getName();
  }
}

interface Driver {
  getName(): string;
}

class DriverImpl implements Driver {
  getName() {
    return "Michael Schumacher";
  }
}

1. Explain to Service Container how to create services, use factories for this:

class CarFactory implements ServiceFactory {
  create(container: ServiceContainer): CarImpl {
    const driver = container.get("driver");
    return new CarImpl(driver);
  }
}

1. Create services Specification:

const spec = new Map();

spec.set("car", new CarFactory());
spec.set("driver", () => new DriverImpl());

If creating a service is trivial, as for driver, we can simply pass a function as a factory. As for class based factory we can pass ServiceContainer as a function parameter.

1. Create Service Container with this Specification:

const serviceContainer = new ServiceContainer(spec);

1. Get some service and call its method:

const car: Car = serviceContainer.get("car");

console.log(car.getDriverName());

1. Get string "Michael Schumacher".