如何在套接字函数之外使用(socket.io)emit函数-Node.js，Express

我有以下代码

var app = require('express')();
var http = require('http');
var server = http.createServer();
var socket = require('socket.io');
var io = socket.listen( server );

io.sockets.on('connection', function(socket) {
  console.log('socket connected');
  socket.broadcast.emit('newUser', 'New User Joined, Say Hi :D');

  socket.on('serverEmit',function(msg) {
    console.log('works');
  });

  socket.on('chatMessage', function(msg) {
    io.emit('server_emit', msg);
    console.log(msg);
  });
});

server.listen(3500, function() {
  console.log('listening on *:3500');
});

所以我的问题是如何在此套接字连接之外添加一个emit函数.例如，如果我有一个如下所示的获取请求

So my question is how to add an emit function outside of this socket connection. For example, if I have a get request like below

app.get('/link',function(req,res) {
  io.sockets.emit('trigger','triggered'); // Process I want to make
});

谢谢.