Node Dependency Injection

A special thanks to Symfony which was a great inspiration and example for this project.

The Node Dependency Injection component allows you to standardize and centralize the way objects are constructed in your application.

Installation

npm install --save node-dependency-injection

Usage: register and get services

Imagine you have a Mailer class like this:

// services/Mailer.js

export default class Mailer {
  /**
   * @param {ExampleService} exampleService
   */
  constructor(exampleService) {
    this._exampleService = exampleService;
  }

  ...
}

You can register this in the container as a service:

import {ContainerBuilder} from 'node-dependency-injection'
import Mailer from './services/Mailer'
import ExampleService from './services/ExampleService'

let container = new ContainerBuilder()

container
  .register('service.example', ExampleService)

container
  .register('service.mailer', Mailer)
  .addArgument('service.example')

And get services from your container

const mailer = container.get('service.mailer')

Autowire for TypeScript

import {ContainerBuilder, Autowire} from 'node-dependency-injection'

const container = new ContainerBuilder(
  false, 
  '/path/to/src'
)
const autowire = new Autowire(container)
await autowire.process()

or from yaml-json-js configuration

# /path/to/services.yml
services:
  _defaults:
    autowire: true
    rootDir:  "/path/to/src"

You can also get a service from a class definition

import SomeService from '@src/service/SomeService'

container.get(SomeService)

If you are transpiling your Typescript may you need to dump the some kind of service configuration file.

import {ContainerBuilder, Autowire, ServiceFile} from 'node-dependency-injection'

const container = new ContainerBuilder(
  false, 
  '/path/to/src'
)
const autowire = new Autowire(container)
autowire.serviceFile = new ServiceFile('/some/path/to/dist/services.yaml')
await autowire.process()

My proposal for load configuration file in a production environment with transpiling/babel compilation:

if (process.env.NODE_ENV === 'dev') {
  this._container = new ContainerBuilder(false, '/src');
  this._autowire = new Autowire(this._container);
  this._autowire.serviceFile = new ServiceFile('/some/path/to/dist/services.yaml');
  await this._autowire.process();
} else {
  this._container = new ContainerBuilder(false, '/dist');
  this._loader = new YamlFileLoader(this._container);
  await this._loader.load('/some/path/to/dist/services.yaml');
}
await this._container.compile();

Configuration files: how to load and use configuration files

You can also use configuration files to improve your service configuration

# /path/to/file.yml
services:
  service.example:
    class: 'services/ExampleService'

  service.mailer:
    class: 'services/Mailer'
    arguments: ['@service.example']

import {ContainerBuilder, YamlFileLoader} from 'node-dependency-injection'

let container = new ContainerBuilder()
let loader = new YamlFileLoader(container)
await loader.load('/path/to/file.yml')

And get services from your container easily

...
const mailer = container.get('service.mailer')

List of features

Autowire for TypeScript
Configuration files with JS, YAML or JSON.
Multiple configuration files
Custom relative service directory
Compiling container
- Custom compiler pass
- Change definition behaviour
Using a factory to create services
Nullable Dependencies
Public or private services
Service Aliasing
Service Tagging
Parameters Injection
Lazy Services
Deprecate Services
Decorate Services
Synthetic Services
Non Shared Services
Parent and Abstract Services
Custom Logger
Container as Service

Please read full documentation

ExpressJS Usage

If you are using expressJS and you like Node Dependency Injection Framework then I strongly recommend you to use the node-dependency-injection-express-middleware package. That gives you the possibility to retrieve the container from the request.

npm install --save node-dependency-injection-express-middleware

import NDIMiddleware from 'node-dependency-injection-express-middleware'
import express from 'express'

const app = express()

const options = {serviceFilePath: 'some/path/to/config.yml'}
app.use(new NDIMiddleware(options).middleware())

Express Middleware Documentation

TypeScript Usage

If you are using typescript and you like Node Dependency Injection Framework then typing are now provided at node-dependency-injection so you do not have to create custom typing anymore.

npm install --save node-dependency-injection

import { ContainerBuilder } from 'node-dependency-injection'
import MongoClient from './services/MongoClient'
import { Env } from './EnvType'

export async function boot(container = new ContainerBuilder(), env: Env) {
    container.register('Service.MongoClient', MongoClient).addArgument({
        host: env.HOST,
        port: env.PORT,
    })
}