Dependencies

In order for the Service Container to be able to automatically inject dependencies, when resolving components, you must first define them on a target class. The dependencies() decorator is used for this purpose.

import { dependencies } from "@aedart/support/container";

@dependencies('engine')
export default class Car
{
    engine = undefined;
    
    constructor(engine) {
        this.engine = engine;
    }
}

No automatic injection

The dependencies() decorator does not automatically inject anything into your class. It will only associate binding identifiers with the target class, as metadata. This means that you can instantiate a new instance of the class, without any side effects (dependencies must be manually given as arguments to the target class).

const car = new Car();
console.log(car.engine); // undefined

The Service Container's make() method is responsible for reading the defined dependencies, resolve them, and inject them into the target class.

Multiple Dependencies

The dependencies() decorator accepts an arbitrary amount of binding identifiers. This allows you to define multiple dependencies in a single call.

@dependencies(
    'warehouse_manager',
    'api_client',
    'events'
)
export default class Warehouse
{
    manager = undefined;
    apiClient = undefined;
    eventDispatcher = undefined;
    
    constructor(manager, apiClient, dispatcher) {
        this.manager = manager;
        this.apiClient = apiClient;
        this.eventDispatcher = dispatcher;
    }
}