websocket-example1

function initWebsocket(symbol, res)
{
	var symbol = symbol.toLowerCase();
	var msgPrefix= "!!! SOCKET !!!";
    var conn = new WebSocket("wss://stream.binance.com:9443/ws/btcusdt@kline_"+res);

	conn.onopen = function(evt) {
	  console.log(msgPrefix+ "[open] Connection established");
	};

	conn.onmessage = function(event) {
	  console.log(msgPrefix+ `[message] Data received from server: ${event.data}`);
	};

	conn.onclose = function(event) {
		console.log(msgPrefix+  "CLOSED");
	  if (event.wasClean) {
		console.log(`[close] Connection closed cleanly, code=${event.code} reason=${event.reason}`);
	  } else {
		// e.g. server process killed or network down .. event.code is usually 1006 in this case
		console.log('[close] Connection died');
	  }
	};

	conn.onerror = function(error) {
	  console.log(msgPrefix+  `[error] ${error.message}`);
	};

	window.onbeforeunload = function() {
		conn.onclose = function () {}; // disable onclose handler first
		conn.close();
	};
	return conn;
}