Node.js request in function

Question

I'm new to Node, and Javascript in general. I'm working with the request module to get a JSON response from a web service. I'm not sure if it'd be best to turn my request into a function, or embed the request inside of another function. I haven't had any luck either way.

// Module imports
var express = require('express');
var router = express.Router();
var request = require('request');

var options = {
  url: 'https:www.example.com/wow.json',
  auth: {
    user: 'user',
    password: 'pass',
    json: true
  }
}

request(options, function (err, res, body) {
  if (err) {
    console.log(err);
    return;
  }
  requestResult = JSON.parse(body); // All data
  wowUsage = requestResult.publishers[0].used;
});

// Sending data to the template view
router.get('/', function(req, res, next) {
  res.render('template', {tempVar: wowUsage});
});

module.exports = router;

Whenever I start up my web server, this code executes once, and then it's done. Refreshing the page won't load any new information. Should I embed the request in a function, and then call that function in my router.get statement? I tried to nest the request in a function, but I couldn't make that work at all.

Answer 1

If you put the request in a separate function, make sure to add a callback parameter to the new function that gets called with the appropriate data. For example:

function getJSON(callback) {
  request(options, function(err, res, body) {
    if (err)
      return callback(err);
    try {
      callback(null, JSON.parse(body).publishers[0].used);
    } catch (ex) {
      callback(ex);
    }
  });
}

router.get('/', function(req, res, next) {
  getJSON(function(err, wowUsage) {
    if (err) {
      console.log(err.stack);
      return res.status(500);
    }
    res.render('template', {tempVar: wowUsage});
  });
});