Load service from package

Register services from npm packages instead of local project files.

You can load a service from an external package (npm, yarn, etc.) instead of a local project file. This is useful for wrapping Node.js built-in modules or third-party packages as container services.

YAML

Use the package name as class and the exported class name as main:

services:
  foo_emitter:
    class: events
    main: EventEmitter

JSON

{
  "services": {
    "foo_emitter": {
      "class": "events",
      "main": "EventEmitter"
    }
  }
}

JS — using PackageReference

In JavaScript configuration or programmatic registration, use PackageReference to reference an npm package:

import {ContainerBuilder, Definition, PackageReference} from 'node-dependency-injection'

let container = new ContainerBuilder()

// Inject EventEmitter (from the built-in 'events' package) as a constructor argument
container
  .register('app.my_service', MyService)
  .addArgument(new PackageReference('events'))

PackageReference accepts the package name as it appears in node_modules (or Node.js built-ins). The container will require/import the package and inject its default export.

If the package exports a named class, specify the main property in YAML/JSON, or import it directly when registering programmatically:

import {EventEmitter} from 'events'

container.register('foo_emitter', EventEmitter)