PureBasic Forums - English

Code: Select all

var sse_object = null;
var unique_client_id = "ucid"+(Math.random()*10000); // this is for coordinating communication between the server and this client. you might find it necessary if using both SSE and AJAX

function OpenSSELink() {
  sse_object = new EventSource("sse.exe?&clientid="+unique_client_id);
  sse_object.onerror = function(e) { alert("EventSource failed.\n"+e.error); };
  sse_object.onmessage = ReceiveSSE;
}

function ReceiveSSE(e) {
  if (e.data=="DUMMY") {
    console.log("DUMMY SSE");
    // do nothing with dummy messages
  } else {
    console.log("REAL SSE");
    // assuming that the sse.exe is sending JavaScript that just needs to be run, eval() it:
    eval(e.data);
  }
}

function CloseSSELink() {
  if (sse_object) {sse_object.close(); }
}

Code: Select all

clientid.s = GetURLPart("http://www.test.com?"+GetEnvironmentVariable("QUERY_STRING"),"clientid")
If clientid = ""
  ; this is an arbitrary thing, a way to uniquely identify the client to your server. you might find it necessary if using both AJAX and SSE to communicate with the client
  End
EndIf


Macro SendData(unqdta)
  HttpAnswer.s = "Content-type: text/event-stream" +#CRLF$+#CRLF$+ "data: "+unqdta +#CRLF$+#CRLF$
  length = StringByteLength(HttpAnswer,#PB_UTF8) ; UTF8 encoding is mandatory for server-sent events
  *buffer = AllocateMemory(length)
  PokeS(*buffer,HttpAnswer,length,#PB_UTF8)
  WriteConsoleData(*buffer,MemoryStringLength(*buffer,#PB_UTF8|#PB_ByteLength))
  lastsentsomething = Date()
EndMacro


OpenConsole()
lastsentsomething.i = Date()

Repeat 
  ; your code
  ; your code
  ;If your code
  ;  SendData("your code") // in this set-up, the data sent should be JavaScript code - try "alert('Hello from PB! "+Str(Random(9999))+"')"
  ;EndIf
  ; your code
  ; your code
  
  
  ; below is mandatory for keeping the connection alive
  ; if nothing sent to client for 27 seconds, send a dummy message (tell your JavaScript to ignore these messages)
  If (Date()-lastsentsomething)>27
     SendData("DUMMY")
  EndIf
  
  Delay(500) ; change this to whatever you want
ForEver

CloseConsole()