unit lib.livedata;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, event.types, DateUtils;

type

  // Ergebniswerte Callback
  TAsyncLivedataResult = record
    ErroText: String;
    ApplicationTimestamp: String;
    OPCConncetionTimestamp: String;
    ErrorCode: Integer; // Fehlercode im Fehlerfall, sonst 0 (=LIVEDATA_OK)
  end;

  TLivedataCallback = procedure(LivedataResult: TAsyncLivedataResult) of Object;

  TLivedataThread = class(TThread)
    FLivedataResult: TAsyncLivedataResult;
    FCallback: TLivedataCallback;

  protected
    procedure Execute; Override;
    procedure DoCallbackVCL;
  public
    constructor Create(Callback: TLivedataCallback); overload;
  end;

function ExecuteAsync(Callback: TLivedataCallback): Boolean;

implementation


  { EventTypes }

constructor TLivedataThread.Create(Callback: TLivedataCallback);
begin

  inherited Create(TRUE); // Thread gestoppt erzeugen
  FreeOnTerminate := TRUE;

  // Callback definieren
  FCallback := Callback;

  // Thread starten, ruft .Execute auf
  Suspended := FALSE;

end;

procedure TLivedataThread.DoCallbackVCL;
begin
  FCallback(FLivedataResult)
end;

procedure TLivedataThread.Execute;
begin

  // Code....
  
 
  // Callback
  if Assigned(FCallback) then // Callback-Funktion übergeben?
    Synchronize(DoCallbackVCL); // dann VCL-fähig ausführen

end;


function ExecuteAsync(Callback: TLivedataCallback): Boolean;
begin
  Result := TRUE;
  TLivedataThread.Create(Callback);
end;

end.

...

uses
  // Livedata-Lib
  lib.Livedata

...

procedure TForm1.LivedataCallback(Result: TAsyncLivedataResult);
begin

  // foobar

end;

procedure TForm1.TimerRedundancyTimer(Sender: TObject);
begin
  // Aufruf Async Thread
  if lib.Livedata.ExecuteAsync(LivedataCallback) then
  begin
    // OK
  end
  else
    // Error

end;