minimal-examples/ws-server/minimal-ws-server-threads/mount-origin/example.js

   1 var head = 0, tail = 0, ring = new Array();
   2
   3 function get_appropriate_ws_url(extra_url)
   4 {
   5         var pcol;
   6         var u = document.URL;
   7
   8         /*
   9          * We open the websocket encrypted if this page came on an
  10          * https:// url itself, otherwise unencrypted
  11          */
  12
  13         if (u.substring(0, 5) === "https") {
  14                 pcol = "wss://";
  15                 u = u.substr(8);
  16         } else {
  17                 pcol = "ws://";
  18                 if (u.substring(0, 4) === "http")
  19                         u = u.substr(7);
  20         }
  21
  22         u = u.split("/");
  23
  24         /* + "/xxx" bit is for IE10 workaround */
  25
  26         return pcol + u[0] + "/" + extra_url;
  27 }
  28
  29 function new_ws(urlpath, protocol)
  30 {
  31         if (typeof MozWebSocket != "undefined")
  32                 return new MozWebSocket(urlpath, protocol);
  33
  34         return new WebSocket(urlpath, protocol);
  35 }
  36
  37 document.addEventListener("DOMContentLoaded", function() {
  38
  39         ws = new_ws(get_appropriate_ws_url(""), "lws-minimal");
  40         try {
  41                 ws.onopen = function() {
  42                         document.getElementById("r").disabled = 0;
  43                 };
  44
  45                 ws.onmessage =function got_packet(msg) {
  46                         var n, s = "";
  47
  48                         ring[head] = msg.data + "\n";
  49                         head = (head + 1) % 50;
  50                         if (tail === head)
  51                                 tail = (tail + 1) % 50;
  52
  53                         n = tail;
  54                         do {
  55                                 s = s + ring[n];
  56                                 n = (n + 1) % 50;
  57                         } while (n !== head);
  58
  59                         document.getElementById("r").value = s;
  60                         document.getElementById("r").scrollTop =
  61                                 document.getElementById("r").scrollHeight;
  62                 };
  63
  64                 ws.onclose = function(){
  65                         document.getElementById("r").disabled = 1;
  66                 };
  67         } catch(exception) {
  68                 alert("<p>Error " + exception);
  69         }
  70
  71 }, false);