CODEWITHSUNDEEP
javascriptnode.jsexpress
Weston
Weston

Reputation: 143

Modularize functions between files in nodejs

I am miss understanding this concept in nodejs. I want to place a function in a folder at ./models/user lets say to represent a model I use for user. Then I want to use these as functions somewhere else. The issue I always run into is when do something like user.something it doesn't handle like a function. I am misunderstanding how this works.

The model would look something like this:

//model/user.js
function User() {
    this.foo = null;
}

User.prototype.hashPass = function (password, callback) {
    //Code that hashes a password
    callback(err, hash);
};

User.prototype.insertUser = function (email, password, callback) {
    //Code that inserts a user and returns some 'done' callback
    callback(err, done);
};

module.exports = User;

And somewhere else in my program lets say passport.js I want to do this:

//config/passport.js
var User = require('../models/user);
var user = new User();

async.waterfall([
    //how does this look
    //EDIT ATTEMPTED HERE
    user.hashPass(password, function(err, result) {

    }),
    user.insertUser(result, function(err, rows) {

    })
], //some callback );

Made some edits to help to clarify what I am trying to accomplish here.

EDIT: This link shows how to do async waterfalls with multiple callbacks

Code based on EDIT / Understanding: 

async.series([
  function(callback) {
    user.hashPass(password, function(err, result) {
      callback(err,result);
    })
  }
], function(err, result) {
  if (err) return err;
  console.log('test',result);
});

Upvotes: 0

Views: 474

Answers (3)

Nicole
Nicole

Reputation: 1707

The only thing you need to change in your code is to replace the line

module.exports = User;

in your passport.js file by

var User = require('../model/User');

Then you can invoke the functions on user:

user.hashPass(password, function(err, result) {
    user.insertUser(result, function(err, rows) {
      // do something with rows here
    });
});

Upvotes: 1

Ashlee Brown
Ashlee Brown

Reputation: 21

It's not working because you have to 'require' your module in the file you want to use it in and you're creating object methods on a constructor function that does not exist. Instead, you could create a user object (not a constructor function) and set each function to an object property, like this: 

//module file
var user = {
  hashPass: function(password, callback){
   //password-hashing function 
  },
  insertUser: function(email, password, callback){
  //new user function
  }
};

module.exports = user;

Then, in whatever place you want to use it, you do so like this: 

//some other file
var user = require(path-to-module);

user.hashPass(); //pass in all parameters (password, callback)
user.insertUser(); //pass in all parameters (password, callback)

The only potential hang-up about this method is that you'll have to define all of your parameters before calling either object property.

Upvotes: 2

TheVigilant
TheVigilant

Reputation: 720

When we have been requiring custom modules we require them by path .

var User = require('config/passport');
var user = new User();

async.waterfall([
   //how does this look
   //do hashPass here
  ,
  //do insertPass here
], //some callback );

Upvotes: 1

Related Questions