Pascal (Lazarus/Delphi)

Binary.com Tick Stream

See more WebSocket Examples

Tick Stream Request -- Initiate a continuous stream of spot price updates for a given symbol. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Rest,
  Chilkat.WebSocket,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  ws: TWebSocket;
  rest: TRest;
  responseBody: string;
  json: TJsonObject;
  finalFrame: Boolean;
  jsonTickData: TJsonObject;
  receivedFinalFrame: Boolean;
  numTicksReceived: Integer;
  receivedJson: string;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  ws := TWebSocket.Create;

  //  For brevity, this example does not check for errors when etablishing the WebSocket connection.
  //  See Establish WebSocket Connection for more complete sample code for making the connection.

  rest := TRest.Create;

  //  Connect to ws.binaryws.com
  success := rest.Connect('ws.binaryws.com',443,True,False);
  ws.UseConnection(rest);
  ws.AddClientHeaders();

  //  My app_id is 12332.  You'll wnat to use your own...
  responseBody := rest.FullRequestNoBody('GET','/websockets/v3?app_id=12332');
  success := ws.ValidateServerHandshake();
  if (success <> True) then
    begin
      WriteLn(ws.LastErrorText);
      WriteLn(responseBody);
      WriteLn(rest.ResponseHeader);
      Exit;
    end;

  //  Build and send the following message:

  //  {
  //    "ticks": "R_50",
  //    "subscribe": 1
  //  }

  json := TJsonObject.Create;
  json.AppendString('ticks','R_50');
  json.AppendInt('subscribe',1);

  //  Send a full message in a single frame
  finalFrame := True;
  success := ws.SendFrame(json.Emit(),finalFrame);
  if (success <> True) then
    begin
      WriteLn(ws.LastErrorText);
      Exit;
    end;

  jsonTickData := TJsonObject.Create;
  jsonTickData.EmitCompact := False;

  //  Begin reading the tick stream response.
  //  We'll just read the 1st 10 updates and then exit..
  receivedFinalFrame := False;
  numTicksReceived := 0;
  while numTicksReceived < 5 do
    begin

      success := ws.ReadFrame();
      if (success <> True) then
        begin
          WriteLn('Failed to receive a frame');
          WriteLn('ReadFrame fail reason = ' + ws.ReadFrameFailReason);
          WriteLn(ws.LastErrorText);
          Exit;
        end;

      //  The responses we desire are in Text frames, where the opcode = 1.
      if (ws.FrameOpcodeInt = 1) then
        begin
          receivedJson := ws.GetFrameData();

          jsonTickData.Load(receivedJson);
          WriteLn(jsonTickData.Emit());

          numTicksReceived := numTicksReceived + 1;
        end;

    end;

  //  Close the websocket connection.
  success := ws.SendClose(True,1000,'Closing this websocket.');
  if (success <> True) then
    begin
      WriteLn(ws.LastErrorText);
      Exit;
    end;

  //  Read the Close response.
  success := ws.ReadFrame();
  if (success <> True) then
    begin
      WriteLn('ReadFrame fail reason = ' + ws.ReadFrameFailReason);
      WriteLn(ws.LastErrorText);
      Exit;
    end;

  WriteLn('Success.');

  //  The output of the above code is shown here:

  //  {
  //    "echo_req": {
  //      "subscribe": 1,
  //      "ticks": "R_50"
  //    },
  //    "msg_type": "tick",
  //    "tick": {
  //      "ask": "373.8725",
  //      "bid": "373.8325",
  //      "epoch": "1517437456",
  //      "id": "2d3dedf1-45e2-66a5-d0d3-72bd7f0a6ea9",
  //      "quote": "373.8525",
  //      "symbol": "R_50"
  //    }
  //  }
  //  
  //  {
  //    "echo_req": {
  //      "subscribe": 1,
  //      "ticks": "R_50"
  //    },
  //    "msg_type": "tick",
  //    "tick": {
  //      "ask": "373.7952",
  //      "bid": "373.7552",
  //      "epoch": "1517437458",
  //      "id": "2d3dedf1-45e2-66a5-d0d3-72bd7f0a6ea9",
  //      "quote": "373.7752",
  //      "symbol": "R_50"
  //    }
  //  }
  //  
  //  {
  //    "echo_req": {
  //      "subscribe": 1,
  //      "ticks": "R_50"
  //    },
  //    "msg_type": "tick",
  //    "tick": {
  //      "ask": "373.8638",
  //      "bid": "373.8238",
  //      "epoch": "1517437460",
  //      "id": "2d3dedf1-45e2-66a5-d0d3-72bd7f0a6ea9",
  //      "quote": "373.8438",
  //      "symbol": "R_50"
  //    }
  //  }
  //  
  //  {
  //    "echo_req": {
  //      "subscribe": 1,
  //      "ticks": "R_50"
  //    },
  //    "msg_type": "tick",
  //    "tick": {
  //      "ask": "373.7636",
  //      "bid": "373.7236",
  //      "epoch": "1517437462",
  //      "id": "2d3dedf1-45e2-66a5-d0d3-72bd7f0a6ea9",
  //      "quote": "373.7436",
  //      "symbol": "R_50"
  //    }
  //  }
  //  
  //  {
  //    "echo_req": {
  //      "subscribe": 1,
  //      "ticks": "R_50"
  //    },
  //    "msg_type": "tick",
  //    "tick": {
  //      "ask": "373.6870",
  //      "bid": "373.6470",
  //      "epoch": "1517437464",
  //      "id": "2d3dedf1-45e2-66a5-d0d3-72bd7f0a6ea9",
  //      "quote": "373.6670",
  //      "symbol": "R_50"
  //    }
  //  }
  //  
  //  Success.


  ws.Free;
  rest.Free;
  json.Free;
  jsonTickData.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.