Digital-flame

Delphi. Omnithreads. ProgressBar with ForEach

Posted on 28.01.2018 by Stanislav_Panteleev

Example with progress Bar on ForEach abstraction.

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.

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.

Posted in Delphi | Leave a comment

MySQL. Triggers don’t fire on Cascade Delete

Posted on 28.01.2018 by Stanislav_Panteleev

This is fact.
No workaround possible with MySQL Syntax.
Only on client.
The end.

Posted in MySQL | Leave a comment

Delphi.Omnithreads.Future – hunting the value in backGroundThread

Posted on 28.01.2018 by Stanislav_Panteleev

Future is good thread abstraction that hunts for the value in background thread. We can ask backGround thread what is value now.

Calling VCL from backGround is bad idea in that case. For that pupose see

http://www.thedelphigeek.com/2014/07/incrementing-progress-bar-from-foreach.html

Below is example of Future Abstraction From demos…

unit test_39_Futures;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, OtlTask, OtlTaskControl, OtlParallel, Vcl.ComCtrls;

type
  TfrmFuturesDemo = class(TForm)
    btnTestFuture1: TButton;
    lbLog: TListBox;
    btnTestFuture2: TButton;
    btnTestFuture3: TButton;
    btnTestFuture4: TButton;
    btnTestFuture5: TButton;
    btnTestFuture6: TButton;
    btnTestFuture7: TButton;
    bMyFuture: TButton;
    ProgressBar1: TProgressBar;
    procedure FormCreate(Sender: TObject);
    procedure btnTestFuture1Click(Sender: TObject);
    procedure btnTestFuture2Click(Sender: TObject);
    procedure btnTestFuture3Click(Sender: TObject);
    procedure btnTestFuture4Click(Sender: TObject);
    procedure btnTestFuture5Click(Sender: TObject);
    procedure btnTestFuture6Click(Sender: TObject);
    procedure btnTestFuture7Click(Sender: TObject);
    procedure bMyFutureClick(Sender: TObject);
  private
    function CountPrimesTo(high: integer): IOmniFuture<integer>;
    function CountPrimesToHigh(high: integer): integer;
    function CountProgress(high: integer): integer;
    function CountPrimesToMethod: integer;
  public
  end;

var
  frmFuturesDemo: TfrmFuturesDemo;

implementation

uses
  OtlCommon;

{$R *.dfm}
{$I OtlOptions.inc}

const
  CPrimesHigh = 1000000;
  CProgressMax = 100;

function IsPrime(i: integer): boolean;
var
  j: integer;
begin
  Result := false;
  if i <= 1 then
    Exit;
  for j := 2 to Round(Sqrt(i)) do
    if (i mod j) = 0 then
      Exit;
  Result := true;
end;

function CountPrimesToFunc(const task: IOmniTask): integer;
var
  i: integer;
begin
  Result := 0;
  for i := 1 to CPrimesHigh do
    if IsPrime(i) then
    begin
      Inc(Result);
      if task.CancellationToken.IsSignalled then
        Exit;
    end;
end;

procedure TfrmFuturesDemo.FormCreate(Sender: TObject);
begin
  {$IFNDEF Unicode}
  btnTestFuture7.Enabled := false;
  {$ENDIF Unicode}
end;

{ TfrmFuturesDemo }

procedure TfrmFuturesDemo.bMyFutureClick(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use method instead of delegate, test IsDone.
//  numPrimes := TOmniFuture<integer>.Create(CountProgress(100));
 {
  numPrimes := TOmniFuture<integer>.Create(
    function: integer
    begin
      Result := Create(CountProgress(CPrimesHigh));
    end);
  while not numPrimes.IsDone do
  begin
    //Sleep(200);
    ProgressBar1.Position := numPrimes.Value;
    lbLog.Items.Add('in progress ... not yet done');
    lbLog.Update;
  end;
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
  }


  begin
  // Use function-calling delegate.
    numPrimes := TOmniFuture<integer>.Create(
      function: integer
      begin
        Result := CountProgress(CProgressMax);
      end);
//   do something else
    while not numPrimes.IsDone do
    begin
    Sleep(200);
      //ProgressBar1.Position := numPrimes.Value; // bad idea to call vcl from backgroundThread
      // read http://www.thedelphigeek.com/2014/07/incrementing-progress-bar-from-foreach.html
      lbLog.Items.Add('in progress ... not yet done');
      lbLog.Update;
    end;
    lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
  end;
end;

procedure TfrmFuturesDemo.btnTestFuture1Click(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use future-generating method; call Value twice for testing.
  numPrimes := CountPrimesTo(CPrimesHigh);
//   do something else
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture2Click(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use fully coded delegate, create future twice for testing.
  numPrimes := TOmniFuture<integer>.Create(
    function: integer
    begin
      Result := 0
    end);
  numPrimes := TOmniFuture<integer>.Create(
    function: integer
    var
      i: integer;
    begin
      Result := 0;
      for i := 1 to CPrimesHigh do
        if IsPrime(i) then
          Inc(Result);
    end);
//   do something else
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture3Click(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use function-calling delegate.
  numPrimes := TOmniFuture<integer>.Create(
    function: integer
    begin
      Result := CountPrimesToHigh(CPrimesHigh);
    end);
//   do something else
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture4Click(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use method instead of delegate, test IsDone.
  numPrimes := TOmniFuture<integer>.Create(CountPrimesToMethod);
  while not numPrimes.IsDone do
  begin
    Sleep(200);
    lbLog.Items.Add('... not yet done');
    lbLog.Update;
  end;
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture5Click(Sender: TObject);
var
  numPrimes: IOmniFuture<integer>;
begin
  // Use function instead of delegate, test Cancel, IsCancelled and Value after cancellation (must raise exception).
  numPrimes := TOmniFuture<integer>.CreateEx(CountPrimesToFunc);
  Sleep(200);
  if not numPrimes.IsDone then
  begin
    lbLog.Items.Add('... not yet done, canceling');
    lbLog.Update;
    numPrimes.Cancel;
  end;
  lbLog.Items.Add(Format('... IsCancelled = %s', [BoolToStr(numPrimes.IsCancelled, true)]));
  lbLog.Items.Add(Format('... IsDone = %s', [BoolToStr(numPrimes.IsDone, true)]));
  lbLog.Update;
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture6Click(Sender: TObject);
var
  countPrimes: integer;
  numPrimes: IOmniFuture<integer>;
begin
  // Test TryValue.
  numPrimes := TOmniFuture<integer>.Create(CountPrimesToMethod);
  while not numPrimes.TryValue(200, countPrimes) do
  begin
    lbLog.Items.Add('... not yet done');
    lbLog.Update;
  end;
  lbLog.Items.Add(Format('%d primes from 1 to %d', [countPrimes, CPrimesHigh]));
end;

procedure TfrmFuturesDemo.btnTestFuture7Click(Sender: TObject);
{$IFDEF Unicode}
var
  numPrimes: IOmniFuture<integer>;
{$ENDIF Unicode}
begin
  {$IFDEF Unicode}
  numPrimes := TOmniFuture<integer>.Create(
    function: integer
    begin
      Result := Parallel.ForEach(1, CPrimesHigh).AggregateSum.Execute(
        procedure(const value: integer; var result: TOmniValue)
        begin
          if IsPrime(value) then
            result := 1;
        end);
    end);
//   do something else
  lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));
  {$ENDIF Unicode}
end;

function TfrmFuturesDemo.CountPrimesTo(high: integer): IOmniFuture<integer>;
begin
  Result := Parallel.Future<integer>(
    function: integer
    var
      i: integer;
    begin
      Result := 0;
      for i := 1 to high do
        if IsPrime(i) then
          Inc(Result);
    end);
end;

function TfrmFuturesDemo.CountPrimesToHigh(high: integer): integer;
var
  i: integer;
begin
  Result := 0;
  for i := 1 to high do
    if IsPrime(i) then
      Inc(Result);
end;

function TfrmFuturesDemo.CountProgress(high: integer): integer;
var
  i: Integer;
begin
  for i := 0 to high - 1 do
  begin
    sleep(500);
    result := i;
  end;
end;

function TfrmFuturesDemo.CountPrimesToMethod: integer;
begin
  Result := CountPrimesToHigh(CPrimesHigh);
end;

end.

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

unit test_39_Futures;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs, StdCtrls, OtlTask, OtlTaskControl, OtlParallel, Vcl.ComCtrls;

type

TfrmFuturesDemo = class(TForm)

btnTestFuture1: TButton;

lbLog: TListBox;

btnTestFuture2: TButton;

btnTestFuture3: TButton;

btnTestFuture4: TButton;

btnTestFuture5: TButton;

btnTestFuture6: TButton;

btnTestFuture7: TButton;

bMyFuture: TButton;

ProgressBar1: TProgressBar;

procedure FormCreate(Sender: TObject);

procedure btnTestFuture1Click(Sender: TObject);

procedure btnTestFuture2Click(Sender: TObject);

procedure btnTestFuture3Click(Sender: TObject);

procedure btnTestFuture4Click(Sender: TObject);

procedure btnTestFuture5Click(Sender: TObject);

procedure btnTestFuture6Click(Sender: TObject);

procedure btnTestFuture7Click(Sender: TObject);

procedure bMyFutureClick(Sender: TObject);

private

function CountPrimesTo(high: integer): IOmniFuture<integer>;

function CountPrimesToHigh(high: integer): integer;

function CountProgress(high: integer): integer;

function CountPrimesToMethod: integer;

public

end;

var

frmFuturesDemo: TfrmFuturesDemo;

implementation

uses

OtlCommon;

{$R *.dfm}

{$I OtlOptions.inc}

const

CPrimesHigh = 1000000;

CProgressMax = 100;

function IsPrime(i: integer): boolean;

var

j: integer;

begin

Result := false;

if i <= 1 then

Exit;

for j := 2 to Round(Sqrt(i)) do

if (i mod j) = 0 then

Exit;

Result := true;

end;

function CountPrimesToFunc(const task: IOmniTask): integer;

var

i: integer;

begin

Result := 0;

for i := 1 to CPrimesHigh do

if IsPrime(i) then

begin

Inc(Result);

if task.CancellationToken.IsSignalled then

Exit;

end;

procedure TfrmFuturesDemo.FormCreate(Sender: TObject);

begin

{$IFNDEF Unicode}

btnTestFuture7.Enabled := false;

{$ENDIF Unicode}

end;

{ TfrmFuturesDemo }

procedure TfrmFuturesDemo.bMyFutureClick(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use method instead of delegate, test IsDone.

// numPrimes := TOmniFuture<integer>.Create(CountProgress(100));

{

numPrimes := TOmniFuture<integer>.Create(

function: integer

begin

Result := Create(CountProgress(CPrimesHigh));

end);

while not numPrimes.IsDone do

begin

//Sleep(200);

ProgressBar1.Position := numPrimes.Value;

lbLog.Items.Add('in progress ... not yet done');

lbLog.Update;

end;

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

}

begin

// Use function-calling delegate.

numPrimes := TOmniFuture<integer>.Create(

function: integer

begin

Result := CountProgress(CProgressMax);

end);

// do something else

while not numPrimes.IsDone do

begin

Sleep(200);

//ProgressBar1.Position := numPrimes.Value; // bad idea to call vcl from backgroundThread

// read http://www.thedelphigeek.com/2014/07/incrementing-progress-bar-from-foreach.html

lbLog.Items.Add('in progress ... not yet done');

lbLog.Update;

end;

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture1Click(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use future-generating method; call Value twice for testing.

numPrimes := CountPrimesTo(CPrimesHigh);

// do something else

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture2Click(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use fully coded delegate, create future twice for testing.

numPrimes := TOmniFuture<integer>.Create(

function: integer

begin

Result := 0

end);

numPrimes := TOmniFuture<integer>.Create(

function: integer

var

i: integer;

begin

Result := 0;

for i := 1 to CPrimesHigh do

if IsPrime(i) then

Inc(Result);

end);

// do something else

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture3Click(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use function-calling delegate.

numPrimes := TOmniFuture<integer>.Create(

function: integer

begin

Result := CountPrimesToHigh(CPrimesHigh);

end);

// do something else

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture4Click(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use method instead of delegate, test IsDone.

numPrimes := TOmniFuture<integer>.Create(CountPrimesToMethod);

while not numPrimes.IsDone do

begin

Sleep(200);

lbLog.Items.Add('... not yet done');

lbLog.Update;

end;

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture5Click(Sender: TObject);

var

numPrimes: IOmniFuture<integer>;

begin

// Use function instead of delegate, test Cancel, IsCancelled and Value after cancellation (must raise exception).

numPrimes := TOmniFuture<integer>.CreateEx(CountPrimesToFunc);

Sleep(200);

if not numPrimes.IsDone then

begin

lbLog.Items.Add('... not yet done, canceling');

lbLog.Update;

numPrimes.Cancel;

end;

lbLog.Items.Add(Format('... IsCancelled = %s', [BoolToStr(numPrimes.IsCancelled, true)]));

lbLog.Items.Add(Format('... IsDone = %s', [BoolToStr(numPrimes.IsDone, true)]));

lbLog.Update;

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture6Click(Sender: TObject);

var

countPrimes: integer;

numPrimes: IOmniFuture<integer>;

begin

// Test TryValue.

numPrimes := TOmniFuture<integer>.Create(CountPrimesToMethod);

while not numPrimes.TryValue(200, countPrimes) do

begin

lbLog.Items.Add('... not yet done');

lbLog.Update;

end;

lbLog.Items.Add(Format('%d primes from 1 to %d', [countPrimes, CPrimesHigh]));

end;

procedure TfrmFuturesDemo.btnTestFuture7Click(Sender: TObject);

{$IFDEF Unicode}

var

numPrimes: IOmniFuture<integer>;

{$ENDIF Unicode}

begin

{$IFDEF Unicode}

numPrimes := TOmniFuture<integer>.Create(

function: integer

begin

Result := Parallel.ForEach(1, CPrimesHigh).AggregateSum.Execute(

procedure(const value: integer; var result: TOmniValue)

begin

if IsPrime(value) then

result := 1;

end);

// do something else

lbLog.Items.Add(Format('%d primes from 1 to %d', [numPrimes.Value, CPrimesHigh]));

{$ENDIF Unicode}

end;

function TfrmFuturesDemo.CountPrimesTo(high: integer): IOmniFuture<integer>;

begin

Result := Parallel.Future<integer>(

function: integer

var

i: integer;

begin

Result := 0;

for i := 1 to high do

if IsPrime(i) then

Inc(Result);

end);

end;

function TfrmFuturesDemo.CountPrimesToHigh(high: integer): integer;

var

i: integer;

begin

Result := 0;

for i := 1 to high do

if IsPrime(i) then

Inc(Result);

end;

function TfrmFuturesDemo.CountProgress(high: integer): integer;

var

i: Integer;

begin

for i := 0 to high - 1 do

begin

sleep(500);

result := i;

end;

function TfrmFuturesDemo.CountPrimesToMethod: integer;

begin

Result := CountPrimesToHigh(CPrimesHigh);

end;

end.

Posted in Delphi | Leave a comment

Delphi. OmniThreads.Async – most simple example

Posted on 28.01.2018 by Stanislav_Panteleev

hi, most simple example of OmniThread lib looks like

procedure TfrmDemoParallelAsync.btnAsyncClick(Sender: TObject);
begin
  btnAsync.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
      btnAsync.Enabled := true;
      Caption := 'Ready';
    end));
end;

procedure TfrmDemoParallelAsync.btnAsyncClick(Sender: TObject);

begin

btnAsync.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

btnAsync.Enabled := true;

Caption := 'Ready';

end));

end;

GUI is responsive during executing the code…

Posted in Delphi | Leave a comment

Delphi. UniGUI. Emulation of Pages using Frames

Posted on 27.01.2018 by Stanislav_Panteleev

UniGUI is SPA – single page application, but, emulation is possible.

One option – use frames.

unit uPagesFramesDM;

interface

uses
  SysUtils, Classes, uPage1Frame, uPage2Frame;

type
  TPagesFramesDM = class(TDataModule)
  private
    FCurrentPage: integer;
    FPage1: TPage1Frame;
    FPage2: TPage2Frame;
    FSomeParent: TObject;
    FHistory: TArray<integer>;
    procedure SetCurrentPage(const Value: integer);
    procedure KillFrames();
    procedure AddHistory(AValue: integer);
    procedure SetMainForm(const Value: TObject);
    procedure SetHistory(const Value: TArray<integer>);

    { Private declarations }
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    procedure Back();
    procedure Next();
    procedure Load(aIndex: integer);
    property SomeParent: TObject read FSomeParent write SetMainForm;
    property CurrentPage: integer read FCurrentPage write SetCurrentPage;
    property History: TArray<integer> read FHistory write SetHistory;
  end;

implementation

uses
  Vcl.Controls, Main, uniGUIApplication;

{$R *.dfm}


{ TDataModule1 }

procedure TPagesFramesDM.AddHistory(AValue: integer);
begin
  SetLength(FHistory, length(FHistory) + 1);
  FHistory[high(FHistory)] := AValue;
end;

procedure TPagesFramesDM.Back;
begin
  if FCurrentPage > 0 then
  begin
    FCurrentPage := FCurrentPage - 1;
    Load(CurrentPage);
  end;
end;

constructor TPagesFramesDM.Create(AOwner: TComponent);
begin
  inherited;
// loadCurrentPage
  FHistory := [0, 1];
end;

procedure TPagesFramesDM.Next;
begin
  if FCurrentPage < High(FHistory) then
  begin
    FCurrentPage := FCurrentPage + 1;
    Load(CurrentPage);
  end;
end;

procedure TPagesFramesDM.KillFrames;
begin
  if assigned(FPage1) then
    FreeAndNil(FPage1);
  if assigned(FPage2) then
    FreeAndNil(FPage2);
end;

procedure TPagesFramesDM.Load(aIndex: integer);
begin
  case aIndex of
    0:
      begin
      // load first page
        killFrames();
        FPage1 := TPage1Frame.Create(MainForm);
        with FPage1 do
        begin
          Parent := MainForm;
          Align := alClient;
          Show();
        end;
      end;
    1:
      begin
      // load second page
        killFrames();
        FPage2 := TPage2Frame.Create(MainForm);
        with FPage2 do
        begin
          Parent := MainForm;
          Align := alClient;
          Show();
        end;
      end;
  end;
end;

procedure TPagesFramesDM.SetCurrentPage(const Value: integer);
begin
  FCurrentPage := Value;
end;

procedure TPagesFramesDM.SetHistory(const Value: TArray<integer>);
begin
  FHistory := Value;
end;

procedure TPagesFramesDM.SetMainForm(const Value: TObject);
begin
  FSomeParent := Value;
end;

end.

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

unit uPagesFramesDM;

interface

uses

SysUtils, Classes, uPage1Frame, uPage2Frame;

type

TPagesFramesDM = class(TDataModule)

private

FCurrentPage: integer;

FPage1: TPage1Frame;

FPage2: TPage2Frame;

FSomeParent: TObject;

FHistory: TArray<integer>;

procedure SetCurrentPage(const Value: integer);

procedure KillFrames();

procedure AddHistory(AValue: integer);

procedure SetMainForm(const Value: TObject);

procedure SetHistory(const Value: TArray<integer>);

{ Private declarations }

public

{ Public declarations }

constructor Create(AOwner: TComponent); override;

procedure Back();

procedure Next();

procedure Load(aIndex: integer);

property SomeParent: TObject read FSomeParent write SetMainForm;

property CurrentPage: integer read FCurrentPage write SetCurrentPage;

property History: TArray<integer> read FHistory write SetHistory;

end;

implementation

uses

Vcl.Controls, Main, uniGUIApplication;

{$R *.dfm}

{ TDataModule1 }

procedure TPagesFramesDM.AddHistory(AValue: integer);

begin

SetLength(FHistory, length(FHistory) + 1);

FHistory[high(FHistory)] := AValue;

end;

procedure TPagesFramesDM.Back;

begin

if FCurrentPage > 0 then

begin

FCurrentPage := FCurrentPage - 1;

Load(CurrentPage);

end;

constructor TPagesFramesDM.Create(AOwner: TComponent);

begin

inherited;

// loadCurrentPage

FHistory := [0, 1];

end;

procedure TPagesFramesDM.Next;

begin

if FCurrentPage < High(FHistory) then

begin

FCurrentPage := FCurrentPage + 1;

Load(CurrentPage);

end;

procedure TPagesFramesDM.KillFrames;

begin

if assigned(FPage1) then

FreeAndNil(FPage1);

if assigned(FPage2) then

FreeAndNil(FPage2);

end;

procedure TPagesFramesDM.Load(aIndex: integer);

begin

case aIndex of

begin

// load first page

killFrames();

FPage1 := TPage1Frame.Create(MainForm);

with FPage1 do

begin

Parent := MainForm;

Align := alClient;

Show();

end;

begin

// load second page

killFrames();

FPage2 := TPage2Frame.Create(MainForm);

with FPage2 do

begin

Parent := MainForm;

Align := alClient;

Show();

end;

procedure TPagesFramesDM.SetCurrentPage(const Value: integer);

begin

FCurrentPage := Value;

end;

procedure TPagesFramesDM.SetHistory(const Value: TArray<integer>);

begin

FHistory := Value;

end;

procedure TPagesFramesDM.SetMainForm(const Value: TObject);

begin

FSomeParent := Value;

end;

end.

Then call its in main like this

unit Main;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, uniGUITypes, uniGUIAbstractClasses, uniGUIClasses, uniGUIRegClasses,
  uniGUIForm, uniGUIBaseClasses, uniPanel, uniButton, uniBitBtn, uPagesFramesDM;

type
  TMainForm = class(TUniForm)
    pMainMenuTop: TUniPanel;
    bPrevious: TUniBitBtn;
    bNext: TUniBitBtn;
    bPage1: TUniBitBtn;
    bPage2: TUniBitBtn;
    procedure bPreviousClick(Sender: TObject);
    procedure bNextClick(Sender: TObject);
    procedure bPage1Click(Sender: TObject);
    procedure bPage2Click(Sender: TObject);
    procedure UniFormAfterShow(Sender: TObject);
  private
    { Private declarations }
    FPages: TPagesFramesDM;
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
  end;

function MainForm: TMainForm;

implementation

{$R *.dfm}

uses
  uniGUIVars, MainModule, uniGUIApplication;

function MainForm: TMainForm;
begin
  Result := TMainForm(UniMainModule.GetFormInstance(TMainForm));
end;

{ TMainForm }

procedure TMainForm.bPage1Click(Sender: TObject);
begin
  FPages.Load(0);
end;

procedure TMainForm.bPage2Click(Sender: TObject);
begin
  FPages.Load(1);
end;

procedure TMainForm.bPreviousClick(Sender: TObject);
begin
  FPages.Back();
end;

constructor TMainForm.Create(AOwner: TComponent);
begin
  inherited;
  FPages := TPagesFramesDM.Create(UniApplication);
  FPages.SomeParent := Self;
end;

procedure TMainForm.UniFormAfterShow(Sender: TObject);
begin
  FPages.Load(0);
end;

procedure TMainForm.bNextClick(Sender: TObject);
begin
  FPages.Next()
end;

initialization
  RegisterAppFormClass(TMainForm);

end.

unit Main;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs, uniGUITypes, uniGUIAbstractClasses, uniGUIClasses, uniGUIRegClasses,

uniGUIForm, uniGUIBaseClasses, uniPanel, uniButton, uniBitBtn, uPagesFramesDM;

type

TMainForm = class(TUniForm)

pMainMenuTop: TUniPanel;

bPrevious: TUniBitBtn;

bNext: TUniBitBtn;

bPage1: TUniBitBtn;

bPage2: TUniBitBtn;

procedure bPreviousClick(Sender: TObject);

procedure bNextClick(Sender: TObject);

procedure bPage1Click(Sender: TObject);

procedure bPage2Click(Sender: TObject);

procedure UniFormAfterShow(Sender: TObject);

private

{ Private declarations }

FPages: TPagesFramesDM;

public

{ Public declarations }

constructor Create(AOwner: TComponent); override;

end;

function MainForm: TMainForm;

implementation

{$R *.dfm}

uses

uniGUIVars, MainModule, uniGUIApplication;

function MainForm: TMainForm;

begin

Result := TMainForm(UniMainModule.GetFormInstance(TMainForm));

end;

{ TMainForm }

procedure TMainForm.bPage1Click(Sender: TObject);

begin

FPages.Load(0);

end;

procedure TMainForm.bPage2Click(Sender: TObject);

begin

FPages.Load(1);

end;

procedure TMainForm.bPreviousClick(Sender: TObject);

begin

FPages.Back();

end;

constructor TMainForm.Create(AOwner: TComponent);

begin

inherited;

FPages := TPagesFramesDM.Create(UniApplication);

FPages.SomeParent := Self;

end;

procedure TMainForm.UniFormAfterShow(Sender: TObject);

begin

FPages.Load(0);

end;

procedure TMainForm.bNextClick(Sender: TObject);

begin

FPages.Next()

end;

initialization

RegisterAppFormClass(TMainForm);

end.

Posted in Delphi | Leave a comment

RTTI Atributes

Posted on 26.01.2018 by Stanislav_Panteleev

shows how to work with RTTI and attributes

RTTI – Run Time Type Library – is approach that helps to manage code when program is running.

Lets say we have code from someOne without docs. RTTI will help to find methods, invoke them, get / set properties, fields, work with attributes (some meta-information to classes)

defining attributes as derivative from TCustomAttribute

SomeAttribute = class(TCustomAttribute)
  private
    FText: string;
    FText2: string;
    FAge: integer;
    procedure SetText(const Value: string);
    procedure SetText2(const Value: string);
    procedure SetAge(const Value: integer);
  published
    constructor Create(AText: string; AText2: string; AAge: integer);
    property Text: string read FText write SetText;
    property Text2: string read FText2 write SetText2;
    property Age: integer read FAge write SetAge;
  end;

SomeAttribute = class(TCustomAttribute)

private

FText: string;

FText2: string;

FAge: integer;

procedure SetText(const Value: string);

procedure SetText2(const Value: string);

procedure SetAge(const Value: integer);

published

constructor Create(AText: string; AText2: string; AAge: integer);

property Text: string read FText write SetText;

property Text2: string read FText2 write SetText2;

property Age: integer read FAge write SetAge;

end;

constructor SomeAttribute.Create(AText: string; AText2: string; AAge: integer);
begin
  FText := AText;
  FTExt2 := AText2;
  FAge := AAge;
end;

constructor SomeAttribute.Create(AText: string; AText2: string; AAge: integer);

begin

FText := AText;

FTExt2 := AText2;

FAge := AAge;

end;

assigning attributes to elements of class

 [SomeAttribute('text','text2',123)]
  TSomeClass = class
  public
    [SomeAttribute('text3','text4',1234)]
    function someProcedure(const s: string): string;
    [SomeAttribute('text5','text6',12345)]
    function anotherProcedure(const s: string): string;
  end;

[SomeAttribute('text','text2',123)]

TSomeClass = class

public

[SomeAttribute('text3','text4',1234)]

function someProcedure(const s: string): string;

[SomeAttribute('text5','text6',12345)]

function anotherProcedure(const s: string): string;

end;

reading attributes

procedure TMain.bStartClick(Sender: TObject);
var
  ctx: TRttiContext;
  t: TRttiType;
  m: TRttiMethod;
  a: TCustomAttribute;
begin
  Memo.Lines.Clear;
  ctx := TRttiContext.Create;
  try
    t := ctx.GetType(TSomeClass); //
    for m in t.GetMethods do
    //  if m.Visibility=mvPublic  then Memo.Lines.Add(m.Name);
      for a in m.GetAttributes() do
        if (a is SomeAttribute) then
        begin
          Memo.Lines.Add(Format('Method = %s; Attribute = %s, Text = %s,Text2 = %s Age = %d', [m.Name, a.ClassName, SomeAttribute(a).Text, SomeAttribute(a).Text2, SomeAttribute(a).Age]));
        end;
  finally
    ctx.Free;
  end;
end;

procedure TMain.bStartClick(Sender: TObject);

var

ctx: TRttiContext;

t: TRttiType;

m: TRttiMethod;

a: TCustomAttribute;

begin

Memo.Lines.Clear;

ctx := TRttiContext.Create;

try

t := ctx.GetType(TSomeClass); //

for m in t.GetMethods do

// if m.Visibility=mvPublic then Memo.Lines.Add(m.Name);

for a in m.GetAttributes() do

if (a is SomeAttribute) then

begin

Memo.Lines.Add(Format('Method = %s; Attribute = %s, Text = %s,Text2 = %s Age = %d', [m.Name, a.ClassName, SomeAttribute(a).Text, SomeAttribute(a).Text2, SomeAttribute(a).Age]));

end;

finally

ctx.Free;

end;

Posted in Delphi | Leave a comment

C#. Undirected Graph Basics Altogether

Posted on 16.01.2018 by Stanislav_Panteleev

Git

Graph

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GraphBasics
{
    public class Graph
    {
        public int V { get; set; }
        public int E { get; set; }
        public Bag<int>[] adj;
        public Graph(int V) // init empty graph with V verticles
        {
            if (V < 0)
            {
                throw new ArgumentException();
            }

            this.V = V;
            this.E = 0;
            adj = new Bag<int>[V];
            for (int v = 0; v <= V; v++)
            {
                adj[v] = new Bag<int>();
            }
        }
        public Graph(string aFilePath) // init graph from filePath
        {
       
            if (!File.Exists(aFilePath)) throw new Exception("file not exists");
            string[] ReadText = File.ReadAllLines(aFilePath);
            this.V = Convert.ToInt32(ReadText[0]);
            this.E = 0; //Convert.ToInt32(ReadText[1]);
            // init adj obj
            adj = new Bag<int>[V];
            for (int v = 0; v < V; v++)
            {
                adj[v] = new Bag<int>();
            }
            for (var i = 2; i < ReadText.Length; i++)
            {
                string[] splitted;
                splitted = ReadText[i].Split(' ');
                //if (splitted.Count<string> = 2)
                {
                    int v = Convert.ToInt32(splitted[0]);
                    int w = Convert.ToInt32(splitted[1]);
                    this.AddEdge(v, w);
                }

            }
        }
        // vertices and edges
        public int Vertices() { return V; }
        public int Edges() { return E; }
        public void ValidateVertex(int v)
        {
            if (v < 0 || v > V) { throw new ArgumentException(); }
        }
        // adding undirected edge to the graph
        public void AddEdge(int v, int w)
        {
            ValidateVertex(v);
            ValidateVertex(w);
            E++;
            adj[v].Push(w);
            adj[w].Push(v);
        }
        //returns vertices adjacent to vertex
        public Bag<int> AdjacentVerticles(int v)
        {
            ValidateVertex(v);
            return adj[v];
        }
        // returns degree of vertex
        public int Degree(int v)
        {
            ValidateVertex(v);
            return adj[v].Size();
        }
        // returns string representation of Graph
        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(V + " vertices, " + E + " edges " + "\n");
            for (var v = 0; v < V; v++)
            {
                sb.Append(v + ":");
                foreach (int w in adj[v])
                {
                    sb.Append(w + " ");
                }
                sb.AppendLine();
            }
            return sb.ToString();
        }
    }
}

100

101

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace GraphBasics

{

public class Graph

{

public int V { get; set; }

public int E { get; set; }

public Bag<int>[] adj;

public Graph(int V) // init empty graph with V verticles

{

if (V < 0)

{

throw new ArgumentException();

}

this.V = V;

this.E = 0;

adj = new Bag<int>[V];

for (int v = 0; v <= V; v++)

{

adj[v] = new Bag<int>();

}

public Graph(string aFilePath) // init graph from filePath

{

if (!File.Exists(aFilePath)) throw new Exception("file not exists");

string[] ReadText = File.ReadAllLines(aFilePath);

this.V = Convert.ToInt32(ReadText[0]);

this.E = 0; //Convert.ToInt32(ReadText[1]);

// init adj obj

adj = new Bag<int>[V];

for (int v = 0; v < V; v++)

{

adj[v] = new Bag<int>();

}

for (var i = 2; i < ReadText.Length; i++)

{

string[] splitted;

splitted = ReadText[i].Split(' ');

//if (splitted.Count<string> = 2)

{

int v = Convert.ToInt32(splitted[0]);

int w = Convert.ToInt32(splitted[1]);

this.AddEdge(v, w);

}

// vertices and edges

public int Vertices() { return V; }

public int Edges() { return E; }

public void ValidateVertex(int v)

{

if (v < 0 || v > V) { throw new ArgumentException(); }

}

// adding undirected edge to the graph

public void AddEdge(int v, int w)

{

ValidateVertex(v);

ValidateVertex(w);

E++;

adj[v].Push(w);

adj[w].Push(v);

}

//returns vertices adjacent to vertex

public Bag<int> AdjacentVerticles(int v)

{

ValidateVertex(v);

return adj[v];

}

// returns degree of vertex

public int Degree(int v)

{

ValidateVertex(v);

return adj[v].Size();

}

// returns string representation of Graph

public override string ToString()

{

StringBuilder sb = new StringBuilder();

sb.Append(V + " vertices, " + E + " edges " + "\n");

for (var v = 0; v < V; v++)

{

sb.Append(v + ":");

foreach (int w in adj[v])

{

sb.Append(w + " ");

}

sb.AppendLine();

}

return sb.ToString();

}

Continue reading →

Posted in C# | Leave a comment

Delphi IDE Colorizer – did you know about?

Posted on 14.01.2018 by Stanislav_Panteleev

Yesterday opened for myself Delphi IDE Colorizer (DIC). Cool thing – see attachment pic !!!

It has dozens of themes, transparent menu, with Delphi Theme Editor together you can customize IDE as you wish. And it is free.

I downloaded it from Installer on github

github Source.

Also you will need to customize code area…

Delphi theme editor

Delphi theme editor installer

Posted in Delphi | Leave a comment

MySQL. Cравнение даты (datetime) через оператор BETWEEN

Posted on 06.01.2018 by Stanislav_Panteleev

Источник

Оператор BETWEEN идеально подходит для сравнения диапазона между датами (datetime). Но тут есть подводные камни. Например, есть задача — выбрать данные из таблицы за некоторый промежуток времени (с ‘2008-08-14’ по ‘2008-08-23’).

Рекомендации:
1. Выполняя любые сравнения, приводить все данные к одному типу.
2. Если один операнд имеет значение типа TIMESTAMP или DATETIME, а другой является константой, операнды сравниваются как значения типа TIMESTAMP. А это значит, что если была строка в виде ‘2008-08-14’, то она автоматически преобразуется в TIMESTAMP ‘2008-08-14 00:00:00’ и это влияет на результат запроса.
3. Над данными, которые участвуют в условиях сравнения желательно не делать никаких операций — это позволяет для них использовать индексы, иначе они игнорируются.

# Поле created_at - тип DATETIME
# КОРРЕКТНЫЕ ЗАПРОСЫ
 
# 1: Индексы для created_at поля не используются. 
# Условие BETWEEN '2008-08-14' AND '2008-08-23'
# преобразуется в BETWEEN '2008-08-14 00:00:00' AND '2008-08-23 00:00:00'.
SELECT * FROM news
  WHERE DATE(created_at) BETWEEN '2008-08-14' AND '2008-08-23';
 
# 2: Оператор BETWEEN не используем, но тоже не самый лучший вариант, индексы не используются
SELECT * FROM news
  WHERE DATE(created_at) >= '2008-08-14' AND DATE(created_at) <= '2008-08-23';
 
# 3: Строки '2008-08-14 00:00:00' и '2008-08-23 23:59:59' не приведены к типу данных DATE
SELECT * FROM news
  WHERE created_at BETWEEN '2008-08-14 00:00:00' AND '2008-08-23 23:59:59';
 
# 4: Самый лучший вариант, привели к типу DATETIME, индексы будут использоваться
SELECT * FROM news
  WHERE created_at BETWEEN STR_TO_DATE('2008-08-14 00:00:00', '%Y-%m-%d %H:%i:%s') 
  AND STR_TO_DATE('2008-08-23 23:59:59', '%Y-%m-%d %H:%i:%s');
 
 
#############################
# НЕПРАВИЛЬНЫЕ ЗАПРОСЫ
 
# 5: Строки '2008-08-14' и '2008-08-23' преобразуются в TIMESTAMP и дополняются '00:00:00'
SELECT * FROM news 
  WHERE created_at >= '2008-08-14' AND created_at <= '2008-08-23';
 
# 6: Аналогично запросу 5
SELECT * FROM news 
  WHERE created_at BETWEEN STR_TO_DATE('2008-08-14', '%Y-%m-%d') AND STR_TO_DATE('2008-08-23', '%Y-%m-%d');

# Поле created_at - тип DATETIME

# КОРРЕКТНЫЕ ЗАПРОСЫ

# 1: Индексы для created_at поля не используются.

# Условие BETWEEN '2008-08-14' AND '2008-08-23'

# преобразуется в BETWEEN '2008-08-14 00:00:00' AND '2008-08-23 00:00:00'.

SELECT * FROM news

WHERE DATE(created_at) BETWEEN '2008-08-14' AND '2008-08-23';

# 2: Оператор BETWEEN не используем, но тоже не самый лучший вариант, индексы не используются

SELECT * FROM news

WHERE DATE(created_at) >= '2008-08-14' AND DATE(created_at) <= '2008-08-23';

# 3: Строки '2008-08-14 00:00:00' и '2008-08-23 23:59:59' не приведены к типу данных DATE

SELECT * FROM news

WHERE created_at BETWEEN '2008-08-14 00:00:00' AND '2008-08-23 23:59:59';

# 4: Самый лучший вариант, привели к типу DATETIME, индексы будут использоваться

SELECT * FROM news

WHERE created_at BETWEEN STR_TO_DATE('2008-08-14 00:00:00', '%Y-%m-%d %H:%i:%s')

AND STR_TO_DATE('2008-08-23 23:59:59', '%Y-%m-%d %H:%i:%s');

#############################

# НЕПРАВИЛЬНЫЕ ЗАПРОСЫ

# 5: Строки '2008-08-14' и '2008-08-23' преобразуются в TIMESTAMP и дополняются '00:00:00'

SELECT * FROM news

WHERE created_at >= '2008-08-14' AND created_at <= '2008-08-23';

# 6: Аналогично запросу 5

SELECT * FROM news

WHERE created_at BETWEEN STR_TO_DATE('2008-08-14', '%Y-%m-%d') AND STR_TO_DATE('2008-08-23', '%Y-%m-%d');

Получаем самый лучший запрос:

SELECT * FROM news
  WHERE created_at BETWEEN STR_TO_DATE('2008-08-14 00:00:00', '%Y-%m-%d %H:%i:%s') 
  AND STR_TO_DATE('2008-08-23 23:59:59', '%Y-%m-%d %H:%i:%s');

SELECT * FROM news

WHERE created_at BETWEEN STR_TO_DATE('2008-08-14 00:00:00', '%Y-%m-%d %H:%i:%s')

AND STR_TO_DATE('2008-08-23 23:59:59', '%Y-%m-%d %H:%i:%s');

Posted in MySQL | Leave a comment

Delphi. UniGUI. Synchronious and ASynchronious modes

Posted on 20.12.2017 by Stanislav_Panteleev

about ShowModal in VCL and not only

http://www.unigui.com/doc/online_help/synch-and-asynch-operations.htm

Posted in Delphi | Leave a comment

Delphi. Omnithreads. ProgressBar with ForEach

MySQL. Triggers don’t fire on Cascade Delete

Delphi.Omnithreads.Future – hunting the value in backGroundThread

Delphi. OmniThreads.Async – most simple example

Delphi. UniGUI. Emulation of Pages using Frames

RTTI Atributes

C#. Undirected Graph Basics Altogether

Delphi IDE Colorizer – did you know about?

MySQL. Cравнение даты (datetime) через оператор BETWEEN

Delphi. UniGUI. Synchronious and ASynchronious modes

C# WORLD

MySQL WORLD

DELPHI WORLD

JS WORLD

PHP World

IIS World

Recent Posts

Categories