OmniThreads and UniGUI

[elGringo]

Hi, trying example ProgressBar with forEach

but! doesn't work...

vcl example looks like this and works perfectly

unit test_55_ForEachProgress;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics,
  Controls, Forms, Dialogs, StdCtrls, ComCtrls,
 
  OtlTask,
  OtlParallel;
 
type
  TfrmForEachWithProgressBar = class(TForm)
    btnStart : TButton;
    pbForEach: TProgressBar;
    procedure btnStartClick(Sender: TObject);
  private
    FPosition: integer;
    FProgress: integer;
    FWorker  : IOmniParallelLoop<integer>;
    procedure IncrementProgressBar;
  end;
 
var
  frmForEachWithProgressBar: TfrmForEachWithProgressBar;
 
implementation
 
{$R *.dfm}
 
const
  CNumLoop = 20000;
 
procedure TfrmForEachWithProgressBar.btnStartClick(Sender: TObject);
begin
  btnStart.Enabled := false;
 
  pbForEach.Max := 100;
  pbForEach.Position := 0;
  pbForEach.Update;
  FProgress := 0;
  FPosition := 0;
 
  // reference must be kept in a global field so that the task controller is not destroyed before the processing ends
  FWorker := Parallel
    .ForEach(1, CNumLoop)
    .NoWait // important, otherwise message loop will be blocked while ForEach waits for all tasks to terminate
    .OnStop(
      procedure (const task: IOmniTask)
      begin
        // because of NoWait, OnStop delegate is invoked from the worker code; we must not destroy the worker at that point or the program will block
        task.Invoke(
          procedure begin
            FWorker := nil;
            btnStart.Enabled := true;
          end
        );
      end
    );
 
  FWorker.Execute(
    procedure (const task: IOmniTask; const i: integer)
    begin
      // do some work
      Sleep(1);
 
      // update the progress bar
      // we cannot use 'i' for progress as it does not increase sequentially
      // IncrementProgressBar uses internal counter to follow the progress
      task.Invoke(IncrementProgressBar);
    end
  );
end;
 
procedure TfrmForEachWithProgressBar.IncrementProgressBar;
var
  newPosition: integer;
begin
  Inc(FProgress);
  newPosition := Trunc((FProgress / CNumLoop)*pbForEach.Max);
  // make sure we don't overflow TProgressBar with messages
  if newPosition <> FPosition then begin
    pbForEach.Position := newPosition;
    FPosition := newPosition;
  end;
end;
 
end.

On UniGUI i tried...

  ProgressBar.Max := 100;
  ProgressBar.Position := 0;
  ProgressBar.Update;
  FProgress := 0;
  FPosition := 0;
    // reference must be kept in a global field so that the task controller is not destroyed before the processing ends
  FWorker := Parallel.ForEach(1, CNumLoop).NoWait // important, otherwise message loop will be blocked while ForEach waits for all tasks to terminate
    .OnStop(
    procedure(const task: IOmniTask)
    begin
        // because of NoWait, OnStop delegate is invoked from the worker code; we must not destroy the worker at that point or the program will block
      task.Invoke(
        procedure
        begin
          FWorker := nil;
          //btnStart.Enabled := true;
        end);
    end);

  FWorker.Execute(
    procedure(const task: IOmniTask; const i: integer)
    begin
      // do some work
      Sleep(1);

      // update the progress bar
      // we cannot use 'i' for progress as it does not increase sequentially
      // IncrementProgressBar uses internal counter to follow the progress
      task.Invoke(IncrementProgressBar);
    end);

procedure TForeCastSalesByDayCalcFrame.IncrementProgressBar;
var
  newPosition: integer;
begin
  Inc(FProgress);
  newPosition := Trunc((FProgress / CNumLoop) * ProgressBar.Max);
  // make sure we don't overflow TProgressBar with messages
  if newPosition <> FPosition then
  begin
    ProgressBar.Position := newPosition;
    FPosition := newPosition;
  end;
end;

What's wrong?

[elGringo]

Async example seems doesn't work too

[elGringo]

  begin

    bForeCastForDevice.Enabled := false;

    Parallel.Async(

      procedure

      begin

      // executed in background thread

        Caption := 'Work...';

        Sleep(500);

      //  MessageBeep($FFFFFFFF);

      end, Parallel.TaskConfig.OnTerminated(

      procedure(const task: IOmniTaskControl)

      begin

        // executed in main thread

        bForeCastForDevice.Enabled := true;

        Caption := 'Ready';

      end));

  end;

[Oliver Morsch]

I think the problem is that a webapp always works with request -> response. No active request, no response possible.

 

Due to the Async/Nowait you have: request -> response -> Callback function (but here is no request),

[elGringo]

sucks(

as usual will use httpServer on Indy...

[rgreat]

You could use synchronous unigui mode.

[elGringo]

thnks, but already in sunc mode

[aristeo]

To implement a ProgressBar try the attached code.

Main.zip

[rgreat]

thnks, but already in sunc mode

Use UniSession.Synchronize; then.

[elGringo]

Thanks, caisistemas!

Interesting solution with ajax. Also thought about it.

The more i work with UniGUI the more i understand - "first try ajax"))

 

rgreat

What you mean UniSession.Synchronize ?

[rgreat]

for i:=0 to 100 do begin
  pbForEach.Position := i;
  UniSession.Synchronize;
end;

UniSession.Synchronize is more or less analogue of VCL Application.ProcessMessages;

[elGringo]

hm... need to try thnks!