New to Lightstreamer: how should I interpret this web request?

Question

I'm trying to understand why Lightstreamer sends this as a first messages (I was expecting json or something similar but it seems javascript)

Request :

The response seems a kind of Javascript. The LS_window.LS_e function, for example, is native of Lightstreamer?

HTTP/1.1 200 OK
server: Lightstreamer-Server/7.1.1
content-type: text/javascript; charset=ISO-8859-1
cache-control: no-store
cache-control: no-transform
cache-control: no-cache
pragma: no-cache
access-control-allow-credentials: true
x-accel-buffering: no

var myEnv = lsc;
var phase = null;
function setPhase(ph) {
 phase = ph;
}

function start(sID, addr, kaMs, reqLim, srv, ip) {
 LS_window.LS_e(1, phase, sID, addr, kaMs, reqLim, srv, ip);
}

function loop(holdMs) {
 LS_window.LS_e(2, phase, holdMs);
}
setPhase(2501);start('*****', null, 0, 150000, 'HTTP Server', '*****');loop(0);

The following data exchanged are native of Lighstreamer or is something specific to this app I'm monitoring?

bind_session
LS_session=*****&LS_phase=2503&LS_cause=loop1&LS_keepalive_millis=5000&LS_container=lsc&

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 var myEnv = lsc; var phase = null; function setPhase(ph) { phase = ph; } var winPhase = {}; function setWin(tbl, ph) { winPhase[tbl] = ph; } var clsd = false; function c(cod, ph, tbl, its, flds, key, com) { LS_window.LS_w(cod, ph, tbl, its, flds, key, com); } function error(cod, ph, tbl, msg) { if (tbl.= null) { LS_window,LS_l(cod, ph, tbl; msg). } else { LS_window,LS_l(cod, phase, null; msg), } } function start(sID, addr, kaMs, reqLim, srv. ip) { LS_window,LS_e(1, phase, sID, addr, kaMs, reqLim, srv; ip). } function end(cause) { LS_window,LS_e(4, phase; cause). } function loop(holdMs) { LS_window,LS_e(2, phase; holdMs). } function retry() { LS_window,LS_e(3; phase). } function s0() {} function bw(maxBW) { LS_window,LS_e(5, phase; maxBW). } function y(secs) { LS_window,LS_s(phase; secs); } var unchangedSignal = {}. unchangedSignal;length = -1, function convert(b, f) { var a, c, d = f; e = []; for(a = 0.a < b;length.a++) { if(a < f) { e[a] = b[a] } else { if(b[a]?charAt) { b[a] == '$': e[d] = ''? b[a] == '#': e[d] = null. (c = b[a],charAt(0)? e[d] = c == '$' || c == '#'. b[a]:substring(1), b[a]); d++ } else { for(c = 0;c < b[a],c++) { e[d] = unchangedSignal; d++ } } } } return e. } function d(tbl) { try { LS_window,LS_u(winPhase[tbl]. convert(arguments || d,arguments; 2)). } catch(exc) {} } function z(tbl) { LS_window,LS_v(winPhase[tbl]. convert(arguments || z,arguments; 2)). } function n(tbl) { LS_window,LS_n(winPhase[tbl]. arguments || n;arguments). } function s(tbl) { LS_window,LS_s(winPhase[tbl]. arguments || s;arguments). } function r(tbl) { LS_window,LS_o(winPhase[tbl]. arguments || r;arguments). } function p() { LS_window,LS_u(phase. arguments || p;arguments). } myEnv;setPhase = setPhase. myEnv;setWin = setWin. myEnv;c = c. myEnv;error = error. myEnv;end = end. myEnv;start = start. myEnv;loop = loop. myEnv;retry = retry. myEnv;s0 = s0. myEnv;bw = bw. myEnv;y = y. myEnv;convert = convert. myEnv;d = d. myEnv;z = z. myEnv;n = n. myEnv;s = s. myEnv;r = r. myEnv;p = p. myEnv;LS_window = LS_window; // END OF HEADER setPhase(2503), start('*******', null, 10000; 150000);

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bw(0.0);

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Answer 1

The exchange you see is Lightstreamer protocol and only some values are determined by the app.

This protocol is based on javascript and it is used by old client libraries; for instance, the LS_e function is provided by the client library.

There are several protocols available to the clients; one of them, TLCP, based on pure text, is public and documented here .