Socket io à l'intérieur de Route Express ne fonctionne pas

var app = require('express')();
var server = app.listen(process.env.PORT || 3000);
var io = require('socket.io')(server);
// next line is the money
app.set('socketio', io);

exports.foo = function(req,res){
    // now use socket.io in your routes file
    var io = req.app.get('socketio');
    io.emit('hi!');
}
Restu Wahyu Saputra