如何将中间件绑定到socket.io中的事件 [英] how to bind middleware to events in socket.io

问题描述

现在，您可以将中间件绑定到 io.use（中间件）; ，但只有在建立套接字连接时才会触发此操作。有没有办法在将它传递给像expressjs这样的事件句柄之前拦截它？

Right now you can bind middleware to io.use(middleware);, but this is triggered only when a socket connection is made. Is there a way to intercept it before passing it to an event handle like in expressjs?

换句话说....

在 express.js 中你可以这样做：

app.get('/', middleware1, middleware2, function(req, res){
    res.end(); 
});

我可以在 socket.io 中执行相同操作吗？

Can I do the same in socket.io?

socket.on('someEvent', middleware1, middleware2, function(data){
    console.log(data); // data is now filtered by 2 previous middlewares
});

推荐答案

从Socket.io v2.0.4开始（发现这个在检查这个时，您可以像这样使用套接字中间件：

As of Socket.io v2.0.4 (found this while inspecting this) you can use a socket middleware like so:

io.on('connection', (socket) => {
  socket.use((packet, next) => {
    // Handler
    next();
  });
});

这意味着您可以像这样设置代码：

Which means that you can set your code like so:

io.on('connection', (socket) => {
    socket.use((packet,next) => {

        if (packet[0] === 'someEvent') {
            if (authorizationCondition) {
                return next(new Error('nope'))
            }
        }
        next();
    })
    socket.on('someEvent', function(data){
        console.log(data);
    });
})

然后您可以通过客户端捕获这样的错误 - 支持

You will then be able to catch errors like this with a client-side

io.on('error', err => { ... }) // err will equal "nope"

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