server.js

var express = require('express');
var bodyParser = require('body-parser');
var phantom = require('phantom');
var spawn = require('child_process').spawn;

var fs = require('fs');
var screenshot = require('screenshot-stream');

var app = express();
app.use(bodyParser.json());
var public_dir = __dirname + '/public';
app.use(express.static(public_dir));

app.post('/process_url', function (req, res) {
  var url_to_process = req.body.url;
  if (!url_to_process) {
    res.status(404).send({error: "please send correct url"})
  } else {
    var image_file_name = url_to_process.replace(/\W/g, '_') + "-" + (+new Date()) + ".png";
    var image_path = public_dir + "/" + image_file_name;

     var viewpostSize = req.body.viewport;
     var stream = screenshot(url_to_process, viewpostSize || '1366x768');
     stream.pipe(fs.createWriteStream(image_path));
     stream.on('finish', function () {
     res.send({url: image_path, name: image_file_name});
     });


/*    var prc = spawn('phantomjs', ['test.js', url_to_process, image_path ]);
    prc.on('close', function(){
      res.send({url: image_path, name: image_file_name});
    });*/
/*
    phantom.create(function (ph) {
      ph.createPage(function (page) {
        page.open(url_to_process, function (status) {
          if (status == "success") {
            page.render(image_path, function () {
              res.send({url: image_path, name: image_file_name});
            });
          } else {
            res.status(500).send({error: "internal error"})
          }
          page.close();
          ph.exit();
        });
      });
    });*/

  }

});

var server = app.listen(3000, function() {
  console.log('Listening..');
});