how to import modules that require arguments

Question

this is my files sturcture:

-models
    -user.js
    -room.js
    -database.js
-controllers
    -createRoom.js
    -routes.js
    ..

user.js and room.js are modules i want to import in database.js. right now im doing like this:

in database.js:

var mysql = require('mysql');
var Sequelize = require('sequelize');
var db = new Sequelize('test', 'root', 'root', {
dialect: "mysql", 
port: 3306

})
var User = require('./user.js')(Sequelize, db);
var Room = require('./room.js')(Sequelize, db);


module.exports = function(){

    //code...   

};

in user.js/room.js

module.exports = function (Sequelize, db) { 

var Room = db.define('Room', {
    room_id : {type: Sequelize.INTEGER, allowNull: false, autoIncrement: true, primaryKey: true},
})

db
 .sync({force: true})
 .complete(function (err) {})

so far so good, but when i need to import user.js or room.js in other files besides database.js(eg, createRoom.js), i have trouble importing them because theres no Sequelize and db defined like in the database.js. does it mean i have to connect to the database and require Sequelize again whenever i need to use user.js and room.js module in other files? is there a better way to work around this?? thanks!

Answer 1

you have different possibilities here

1. re-export models:

   in your database.js

   //init code as seen
   module.exports.Room = Room
   

   importing somewhere else

   require('../models/database').Room
   

2. make your database.js dependency

   in database.js

    module.export = { Sequelize: Sequelize, db : db}
   

   in room.js

    var dbModule = require('./database')
    module.exports = dbModule.Sequelize.define('Room', /*....*/)
   

3. Attach the model to the init function

   in room.js

   module.exports = roomInit
   
   function roomInit(Sequelize, db) { 
   
     roomInit.Room = db.define('Room', {
       room_id : {type: Sequelize.INTEGER, allowNull: false, autoIncrement: true, primaryKey: true}
   })
   
    db
      .sync({force: true})
      .complete(function (err) {})
    }
   

   usage

    require('./room').Room