I am relatively new to working with Node.js and Express.js. My goal is to set up a websocket server that can send CSV data at irregular intervals stored within the file itself, line by line. The structure of the CSV looks something like this: [timeout [ms], data1, data2, data3 ...]
I have managed to create a functioning websocket server that communicates with the client.
My aim is to find the best solution for achieving the following tasks effectively: 1. Read a line from the CSV file 2. Send that line using WebSockets 3. Pause reading for the time specified in the first value of the row 4. Resume reading after the interval has passed, and repeat the process from step 1.
Although I have made some progress, my current code may not be correct as I'm still learning. It seems like the pause() function is not working as expected.
var $ = require('jquery')
,csv = require('csv');
exports.index = function(server){
var io = require('socket.io').listen(server);
io.sockets.on('connection', function (socket) {
socket.on('startTransmission', function(msg) {
csv()
.from.path('C:/dev/node_express/csv/test.csv', { delimiter: ',', escape: '"' })
.on('record', function(row,index){
var rowArray = $.parseJSON(JSON.stringify(row));
var json = {},
that = this;
$.each(rowArray, function(i,value){
json[keys[i]] = value;
});
socket.emit('transmitDataData', json);
//this.pause(); //I guess around here is where I'd like to pause
// setTimeout(function(){
// that.resume(); //and resume here after the timeout, stored in the first value (rowArray[0])
// }, rowArray[0]);
});
});
});
};
The commented out code unfortunately does not work - All data is sent immediately, row after row, the function doesn't pause