How to send data through sockets?

Question

Node.js

Hello! How can I get data from an ExpressJS handler and "move" it into sockets?

The answer to the question "Why do this at all, if the data is already transmitted via response ?": Some of the data needs to be displayed in real time to all users on the page, and as far as I know, socket.io is designed just for this.

app.post('/test', jsonParser, (req, res) => {
    const dto_test = {
       test: 'asd'
    }

    const test = new Test(dto_test);
    test.generateTest(result => {
        // Здесь каким-то образом нужно передавать данные в сокет ниже.
        res.json({
            result: result.test
        });
    });
});

io.on('connection', (socket) => {
    console.log('a user connected');

    // Будущая отправка данных пользователю.

    socket.on('disconnect', () => {
        console.log('a user disconnected');
    })
})

Answer 1

To send data to everyone, you need to call io.emit

test.generateTest(result => {
  io.emit('some event', { result });
  res.json({
    result: result.test,
  });
});