Snake DI

Extremely minimal dependency injection container tool

Basic usage

Just install the library, import the reflect-metadata shim in your application's entry point and then use the bootstrap method to resolve the dependencies for a class:

It is important to note that the bootstrap method creates an entirely new container using the provided argument as the entry point, but does not allow manipulation of what is inside the container. For manipulating the container, see the global container section below.

// Somewhere in your application
import 'reflect-metadata';

// Where you want to resolve dependencies for a class
const instance = bootstrap<InjectedClass>(InjectedClass);

Injecting properties into classes

This library uses constructor dependency injection, which means you just have to pass the desired type into the properties in the constructor without actually defining them:

@Injectable()
class Something {
  constructor (private other: Other) {}

  get otherThings(): Other {
    return this.other;
  }
}

// And the Other class also needs to use the Injectable decorator

@Injectable()
class Other {}

And Something.otherThings will return the instance of Other as desired.

Using the globally available Container

If you'd like to use a more common approach, there's also a globally available Container class with three static methods: set, get, and remove, which are self-explanatory.

The usage is simple:

// Sets some class inside the container
Container.set(SomeClass);

// Somewhere else in the application
const someClass = Container.get(SomeClass);

// If you wish to remove the reference to the class
Container.remove(SomeClass);

License

MIT