socket.io-stream发射与打开

Question

The socket.io-stream documentation contains the following example for sending and receiving streaming data:

// send data
ss(socket).on('file', function(stream) {
  fs.createReadStream('/path/to/file').pipe(stream);
});

// receive data
ss(socket).emit('file', stream);
stream.pipe(fs.createWriteStream('file.txt'));

According to this example, it seems that we should use "on" to send data and "emit" to receive data. But this seems contrary to all the examples I've seen so far - that we should use "emit" to send data and "on" to receive it. Which is correct? And how should I listen for streaming events?

Answer 1

emit will send a message and on will listen to the message. Now depending on where you are in the server or the client the message will go to the other side ie if you're on the client and you emit then the server will receive and vice versa. What you're doing here is using the npm package socket.io-stream which augments the socket to stream data. The idea is the client requests the image and the server "streams" it to them.