REST data source in NodeJS/ Express MVC Pattern - node.js

Question

What are the best practice to include external REST data sources in an Express MVC application?
Should we create a Model for the entities that we retrieve from external REST sources?
Let's take this practical example :
Our starting point is a user.js model that use mongoose for ODM.
var mongoose = require('mongoose');
var userModel = function () {
//Define a simple schema for our user.
var userSchema = mongoose.Schema({
name: String,
twitterId: Number
});
return mongoose.model('User', userSchema);
};
module.exports = new userModel();
Our objective is to show all tweets for a specific user, so we create a controller controller/userTweets.js where we prepare the data for our View.
How should we include the Twitter REST API in our application to handle this use case? (let's say we are using a nodejs client for twitter apis)
I'm more comfortable to use a specific model for the tweet entity, and then retrieve users tweet from the controller using our model, but how should our tweet.js model looks like?
Or should we design our REST API integration in a different way?

Answer 1

I would create a class called Tweet and a corresponding repository for it.
Assuming you are using es6, because why not.
lets call it tweets.js
'use strict';
module.exports = function (cfg) {
class Tweet {
constructor() {
this.userid = null;
this.text = null;
}
}
class Repo {
static getTweetsForUser(usedId) {
// make a call to twitter api, use https://www.npmjs.com/package/request
// psuedo code
let _ = require('lodash');
getTweets(userid, function (err, tweets) {
return new Promise(function (resolve, reject) {
if (err) {
return reject(err);
}
let data = [],
tweet = new Tweet;
if (! tweets.length) {
return resolve(data);
}
resolve(_.collect(tweets, function (t) {
tweet.userId = userId;
tweet.text = t.getTheTweet;
return tweet;
}));
});
});
}
}
return {
'tweet': Tweet,
'repo' : Repo
}
}
// export whatever modules, like above, lets call it index.js
'use strict';
let _ = require('lodash');
let modules = [
'tweets',
];
// cfg = any app configs that you might need in modules
function init(cfg) {
let core = {};
return _.collect(modules, function (m) {
core[m] = require('./' + m)(cfg);
});
}
module.exports = init;
Example - https://github.com/swarajgiri/express-bootstrap/blob/master/core/index.js
Now in routing side, in your main whatever is your server.js, inject the modules into an instance of express()
app.set('core', require('path/to/core/index')(whateverConfigYouMightNeed))
Once that is done, your route can look something like
'use strict'
let wrap = require('co-wrap');
route.get(':userId/tweets'), wrap(function* (req, res, next) {
let tweets = [];
try {
tweets = yield req.app.get('core').tweets.Repo.getTweetsForUser(req.params.userId)
} catch(e) {
// let the common error handler do its job.
return next(e);
}
// render whatever view you want.
});