lan-jukebox/routes/index.js

var express = require('express');
var router = express.Router();
var bodyParser = require('body-parser');
var expressValidator = require('express-validator');
router.use(bodyParser.urlencoded({extended: true}));
router.use(bodyParser.json());
router.use(expressValidator());

var child_process = require('child_process');

/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'LAN Jukebox' });
});

router.get('/youtube', function(req, res, next) {
  res.render('youtube', { title: 'LAN Jukebox - Add a Youtube Video' });
});

router.use(expressValidator({
    customValidators: {
	dlSuccess: function(video) {
	    // Test if the requested video is available.
	    var youtube_dl = child_process.spawnSync('/usr/bin/youtube-dl', ['-s', video]);
	    console.log(youtube_dl.stderr.toString());
	    if (youtube_dl.stderr.toString()) {
		return false;
	    }
	    return true;
	}
    }
 }
));

router.post('/youtube', function(req, res) {
    var video = req.body.video;
    
    req.checkBody('video', 'URL is not valid.').dlSuccess();
    
    var errors = req.validationErrors();
    
    if(errors){
	res.render('youtube', {
	    title: 'LAN Jukebox - Add a Youtube Video',
	    errors:errors
	});
    } else {
	var youtube_dl = child_process.spawn('/usr/bin/youtube-dl', ['-x', '-o', 'downloads/%(title)s.%(ext)s', video]);
	// TODO eval video
	res.render('index', { title: 'LAN Jukebox' });
    }
});

router.get('/file', function(req, res, next) {
  res.render('file', { title: 'LAN Jukebox - Add a Music File' });
});

module.exports = router;