Factory/Service Locator

boostrap.js

let factory = require('factory'),
db = require('db_module'),
config = require('config');

factory.register('db', function(){
  return new db(config.db);
});


//carry on, db is registered

controller.js

let factory = require('factory'),
DB = factory.get('db');
// Now you can use DB as its already created via the factory, this means we dont need to create it everywhere we use it.

export default class Controller{
  postIndex(req, res){
    //or get here
    let DB = factory.get('db');
    DB.insert('table', req.get('data'));
  }
}

factory.js

class Factory{
  get(key){
    //if created return the instance
    if(this.created(key)){
      return this.created[key];
    }
    //if registered invoke, store and return
    if(this.has(key)){
      return this.create(key);
    }
    //throw error
    throw new Error('not registered');
  }
  register(key, cb){
    this.items[key] = cb;
  }
  //internal helper methods refrenced above....
}

export default new Factory();