var https = require('https');

var express = require('express');
var handlebars = require('express-handlebars')
        .create({ defaultLayout:'main' });

var app = express();
app.engine('handlebars', handlebars.engine);
app.set('view engine', 'handlebars');
app.set('port', process.env.PORT || 3000);
app.set('ip', process.env.IP);

var options = {
  hostname: 'public-api.wordpress.com',
  path: '/rest/v1.1/sites/somesite.wordpress.com/posts/16',
  method: 'GET'
};

app.get('/test', function(req, res) {
  https.request(options, function(restRes) {
    console.log('STATUS: ' + restRes.statusCode);
    res.render('home', { "title": "Test" }); // This code works.
    restRes.on('data', function (jsonResult) {
//      res.render('home', { "title": "Test" }); This code (after removing the line above) does not work.
      console.log('BODY: ' + jsonResult);
    });
  }).end();
});

app.listen(app.get('port'), app.get('ip'), function(){
  console.log( 'Express started on http://' + app.get('ip') + ": " +
    app.get('port') + '; press Ctrl-C to terminate.' );
});

Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:331:11)
    at ServerResponse.header (/home/ubuntu/workspace/node_modules/express/lib/response.js:718:10)
    at ServerResponse.send (/home/ubuntu/workspace/node_modules/express/lib/response.js:163:12)
    at res.render.done (/home/ubuntu/workspace/node_modules/express/lib/response.js:957:10)
    at Immediate._onImmediate (/home/ubuntu/workspace/node_modules/express-handlebars/lib/utils.js:26:13)
    at processImmediate [as _immediateCallback] (timers.js:374:17)