Question

如果将新对象插入数据库，我只需要socket.io向客户端发送消息。所以我的想法是直接从我的控制器的insert-method发出消息。在我的server.js文件中，iam创建了socket.io对象并尝试使其可供其他模块访问：

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

//make socket io accessible for other modules
module.exports.io = io;

在我的控制器中，我尝试以这种方式使用socket.io：

var io = require('../server').io;
...
io.sockets.on("connection", function(socket){
  passportSocketIo.filterSocketsByUser(io, function (user) {
    return user.workingAt === socket.handshake.user.workingAt;
  }).forEach(function(s){
    s.send("news", insertedObject);
  });
});

在这里，我坚持了下来。永远不会触发“连接”事件，因此不会发出消息。这是在单独的文件中使用socket.io的正确方法吗？不幸的是我无法找到复杂的socket.io示例。

Answer 1

您正试图反转控制流程。执行此操作的方法是让控制器实现服务器可用于将控制权传递给的接口（API）。

一个简单的例子是：

在mycontroller.js

// no require needed here, at least, I don't think so

// Controller agrees to implement the function called "respond"
module.exports.respond = function(socket_io){
    // this function expects a socket_io connection as argument

    // now we can do whatever we want:
    socket_io.on('news',function(newsreel){

        // as is proper, protocol logic like
        // this belongs in a controller:

        socket.broadcast.emit(newsreel);
    });
}

现在在server.js：

var io = require('socket.io').listen(80);
var controller = require('./mycontroller');

io.sockets.on('connection', controller.respond );

此示例很简单，因为控制器API看起来与socket.io回调完全相同。但是如果你想将其他参数传递给控制器呢？就像io对象本身或代表端点的变量一样？为此，你需要更多的工作，但它并不多。它基本上与我们经常用来打破或创建闭包的技巧相同：函数生成器：

在mycontroller.js

module.exports.respond = function(endpoint,socket){
    // this function now expects an endpoint as argument

    socket.on('news',function(newsreel){

        // as is proper, protocol logic like
        // this belongs in a controller:

        endpoint.emit(newsreel); // broadcast news to everyone subscribing
                                     // to our endpoint/namespace
    });
}

现在在服务器上我们需要更多工作才能通过终点：

var io = require('socket.io').listen(80);
var controller = require('./mycontroller');

var chat = io
  .of('/chat')
  .on('connection', function (socket) {
      controller.respond(chat,socket);
  });

请注意，我们直接通过socket，但我们通过闭包捕获chat。有了这个，您可以拥有多个端点，每个端点都有自己的控制器：

var io = require('socket.io').listen(80);
var news_controller = require('./controllers/news');
var chat_controller = require('./controllers/chat');

var news = io
  .of('/news')
  .on('connection', function (socket) {
      news_controller.respond(news,socket);
  });

var chat = io
  .of('/chat')
  .on('connection', function (socket) {
      chat_controller.respond(chat,socket);
  });

实际上，您甚至可以为每个端点使用多个控制器。请记住，除订阅事件外，控制器不会执行任何操作。这是正在聆听的服务器：

var io = require('socket.io').listen(80);
var news_controller = require('./controllers/news');
var chat_controller = require('./controllers/chat');

var chat = io
  .of('/chat')
  .on('connection', function (socket) {
      news_controller.respond(chat,socket);
      chat_controller.respond(chat,socket);
  });

它甚至适用于普通的socket.io（没有端点/命名空间）：

var io = require('socket.io').listen(80);
var news_controller = require('./controllers/news');
var chat_controller = require('./controllers/chat');

io.sockets.on('connection', function (socket) {
    news_controller.respond(socket);
    chat_controller.respond(socket);
});

Answer 2

您可以非常容易地做到这一点，您只需要在app.js中编写套接字连接即可，然后您可以在任何需要的地方使用套接字

在app.js文件中放入如下代码

 var http = require('http').createServer(app);
 const io = require('socket.io')(http);  

 io.sockets.on("connection", function (socket) {
 // Everytime a client logs in, display a connected message
 console.log("Server-Client Connected!");

 socket.join("_room" + socket.handshake.query.room_id);

 socket.on('connected', function (data) {

   });
});

const socketIoObject = io;
module.exports.ioObject = socketIoObject;

在任何文件或控制器中，您都可以像下面那样导入该对象

 const socket = require('../app'); //import socket  from app.js

      //you can emit or on the events as shown 
 socket.ioObject.sockets.in("_room" + req.body.id).emit("msg", "How are You ?");

Answer 3

You can solve this problem declaring io instance as global variable.

at the last line of my app.js: IoInstance = require("./socket.io")(server);

at the './socket.io' :
const chatNamespace = require("./namespaces/chat");
const notificationsNamespace = require("./namespaces/notifications");
const auth = require("./middlewares/auth");

module.exports = (server) => {
  const io = require("socket.io").listen(server);

  io.of("/chats")
    .use(auth)
    .on("connect", (socket) => chatNamespace({ io, socket }));

  io.of("/notifications")
    .use(auth)
    .on("connect", (socket) => notificationsNamespace({ io, socket }));

  return io;
};

then, you can use the IoInstance wherever you want, event into your controller. Btw, I could have use it into my namespaces as well, but I've just realized it right now.

example of implementation in the testController.js:

module.exports = async (req, res) => {
  IoInstance.of("/notifications")
    .to("myUserId")
    .emit("sendNotification", ["test", "test1"]);
  return res.send("oioi");
};

在控制器中使用socket.io

3 个答案: