هل هذه الطريقة سليمة من الناحية المنطقية و البرمجية

كود :

[align=left]nit Unit1;[/align]
[align=left]interface[/align]

[align=left]uses[/align]
[align=left]  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,[/align]
[align=left]  Dialogs, StdCtrls, ComCtrls, Unit2,DateUtils;[/align]

[align=left]type[/align]
[align=left]  TForm1 = class(TForm)[/align]
[align=left]    Button1: TButton;[/align]
[align=left]    Edit1: TEdit;[/align]
[align=left]    DateTimePicker1: TDateTimePicker;[/align]
[align=left]    Label1: TLabel;[/align]
[align=left]    Label2: TLabel;[/align]
[align=left]    Edit2: TEdit;[/align]
[align=left]    Label3: TLabel;[/align]
[align=left]    Button2: TButton;[/align]
[align=left]    procedure Button1Click(Sender: TObject);[/align]
[align=left]    procedure Button2Click(Sender: TObject);[/align]
[align=left]  end;[/align]

[align=left]  TEnterEmployee = class(Tds)[/align]
[align=left]  private[/align]
[align=left]   fDateE: TDate;[/align]
[align=left]   procedure SetLDate(ALDate: TDate); override;[/align]
[align=left]   function GetLDate: TDate; override;[/align]
[align=left]  end;[/align]

[align=left]  TSortieEmployee = class(Tds)[/align]
[align=left]  private[/align]
[align=left]   fDateS: TDate;[/align]
[align=left]   procedure SetLDate(ALDate: TDate); override;[/align]
[align=left]   function GetLDate: TDate; override;[/align]
[align=left]  end;[/align]

[align=left]var[/align]
[align=left]  Form1: TForm1;[/align]

[align=left]implementation[/align]

[align=left]{$R *.dfm}[/align]

[align=left]procedure TForm1.Button1Click(Sender: TObject);[/align]
[align=left]var[/align]
[align=left] d1: Tds;[/align]
[align=left]begin[/align]
[align=left] d1:= TEnterEmployee.Create;[/align]
[align=left] try[/align]
[align=left]   d1.NameFirst := Edit1.Text;[/align]
[align=left]   d1.NameLast := Edit2.Text;[/align]
[align=left]   d1.LDate := DateTimePicker1.Date;[/align]
[align=left]   //[/align]
[align=left]   Label1.Caption := d1.NameFirst;[/align]
[align=left]   Label2.Caption := d1.NameLast;[/align]
[align=left]   Label3.Caption := DateToStr(d1.LDate);[/align]
[align=left] finally[/align]
[align=left]  d1.Free[/align]
[align=left] end;[/align]
[align=left]end;[/align]

[align=left]procedure TForm1.Button2Click(Sender: TObject);[/align]
[align=left]var[/align]
[align=left] d1: Tds;[/align]
[align=left]begin[/align]
[align=left] d1:= TSortieEmployee.Create;[/align]
[align=left] try[/align]
[align=left]   d1.NameFirst := Label1.Caption;[/align]
[align=left]   d1.NameLast := Label2.Caption;[/align]
[align=left]   d1.LDate := StrToDate(Label3.Caption);[/align]
[align=left]   //[/align]
[align=left]   Edit1.Text := d1.NameFirst;[/align]
[align=left]   Edit2.Text := d1.NameLast;[/align]
[align=left]   DateTimePicker1.Date := d1.LDate;[/align]
[align=left] finally[/align]
[align=left]  d1.Free[/align]
[align=left] end;[/align]
[align=left]end;[/align]

[align=left]function TEnterEmployee.GetLDate: TDate;[/align]
[align=left]begin[/align]
[align=left]  Result := fDateE[/align]
[align=left]end;[/align]

[align=left]procedure TEnterEmployee.SetLDate(ALDate: TDate);[/align]
[align=left]begin[/align]
[align=left] if YearOf(Now)-YearOf(ALDate)>17 then[/align]
[align=left]   fDateE := ALDate;[/align]
[align=left]end;[/align]

[align=left]function TSortieEmployee.GetLDate: TDate;[/align]
[align=left]begin[/align]
[align=left]  Result := fDateS[/align]
[align=left]end;[/align]

[align=left]procedure TSortieEmployee.SetLDate(ALDate: TDate);[/align]
[align=left]begin[/align]
[align=left]  fDateS := ALDate[/align]
[align=left]end;[/align]

[align=left]end.[/align]

[align=left]-----------[/align]
[align=left]unit Unit2;[/align]

[align=left]interface[/align]
[align=left]uses Controls;[/align]
[align=left]type[/align]
[align=left]  Tds = class[/align]
[align=left]  protected[/align]
[align=left]   fNameFirst,fNameLast: string;[/align]
[align=left]   procedure SetLDate(ALDate: TDate); virtual; abstract;[/align]
[align=left]   function GetLDate: TDate; virtual; abstract;[/align]
[align=left]  public[/align]
[align=left]   property NameFirst: string read fNameFirst write fNameFirst;[/align]
[align=left]   property NameLast: string read fNameLast write fNameLast;[/align]
[align=left]   property LDate: TDate read GetLDate write SetLDate;[/align]
[align=left]  end;[/align]
[align=left]implementation[/align]
[align=left]end.[/align]

كود :

nit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ComCtrls, Unit2,DateUtils;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    DateTimePicker1: TDateTimePicker;
    Label1: TLabel;
    Label2: TLabel;
    Edit2: TEdit;
    Label3: TLabel;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end;

  TEnterEmployee = class(Tds)
  private
   fDateE: TDate;
   procedure SetLDate(ALDate: TDate); override;
   function GetLDate: TDate; override;
  end;

  TSortieEmployee = class(Tds)
  private
   fDateS: TDate;
   procedure SetLDate(ALDate: TDate); override;
   function GetLDate: TDate; override;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
 d1: Tds;
begin
 d1:= TEnterEmployee.Create;
 try
   d1.NameFirst := Edit1.Text;
   d1.NameLast := Edit2.Text;
   d1.LDate := DateTimePicker1.Date;
   //
   Label1.Caption := d1.NameFirst;
   Label2.Caption := d1.NameLast;
   Label3.Caption := DateToStr(d1.LDate);
 finally
  d1.Free
 end;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
 d1: Tds;
begin
 d1:= TSortieEmployee.Create;
 try
   d1.NameFirst := Label1.Caption;
   d1.NameLast := Label2.Caption;
   d1.LDate := StrToDate(Label3.Caption);
   //
   Edit1.Text := d1.NameFirst;
   Edit2.Text := d1.NameLast;
   DateTimePicker1.Date := d1.LDate;
 finally
  d1.Free
 end;
end;

function TEnterEmployee.GetLDate: TDate;
begin
  Result := fDateE
end;

procedure TEnterEmployee.SetLDate(ALDate: TDate);
begin
 if YearOf(Now)-YearOf(ALDate)>17 then
   fDateE := ALDate;
end;

function TSortieEmployee.GetLDate: TDate;
begin
  Result := fDateS
end;

procedure TSortieEmployee.SetLDate(ALDate: TDate);
begin
  fDateS := ALDate
end;

end.