Singleton Classes

[LogSistemas01]

Hello, I'm starting at Unigui and converting a class, a Singleton.

How to deal with this in Unigui, since it will have the same value between sessions and I need it to be different.

It is a User class, where I store data and permissions, but I have other cases as well.

I saw in the manual, an example where a record was created in MainModule, I would not like to have this 'dependency' there, is there another way to do this? Making my class a singleton per session ?

Follow my class to analyze.

type
  TSystem = class
  private
    constructor Create;
    destructor Destroy; override;
    class var FCompany: TCompanyController;
    class var FUser: TUserController;
  public
    class function LogIn(CompanyID: integer = 0; UserID: integer = 0): TCompanyController;
    class function LoggedUser: TCompanyController;
    class function LoggedCompany: TUserController;
  end;

implementation


{ TSistema }

constructor TSystem.Create;
begin

end;

destructor TSystem.Destroy;
begin
  inherited;
end;

class function TSystem.LoggedUser: TCompanyController;
begin
  FCompany.RefreshConn;
  Result := FCompany;
end;

class function TSystem.LogIn(CompanyID: integer = 0; UserID: integer = 0): TCompanyController;
begin
  try
    {Colocar destroy das classes no logout e finalization}

    if not Assigned(FUser) then
      FUser := TUserController.Create;

    if not Assigned(FCompany) then
      FCompany := TCompanyController.Create;

    FCompany.Get( CompanyID );
    FUser.Get( UserID, CompanyID);

    Result := FCompany;
  except
    on E: Exception do
    begin
      Raise;
    end;
  end;
end;

class function TSystem.LoggedCompany: TUserController;
begin
  if not Assigned( FUser ) then
    raise Exception.Create('FUsuarioLogado não instanciado, realize o login na empresa!');

  FUser.RefreshConn;
  Result := FUser;
end;

initialization

finalization
  if Assigned(TSystem.FCompany) then
    FreeAndNil(TSystem.FCompany);

  if Assigned(TSystem.FUser) then
    FreeAndNil(TSystem.FUser);


end.

Example:

Open 2 Sessions

 

1º Session

TSystem.LogIn(1,1);

ShowMessage(TSystem.LoggedUser.User.Name);

Shows 'User 1'.

 

2º Session

TSystem.LogIn(2,2);

ShowMessage(TSystem.LoggedUser.User.Name);

Shows 'User 2'

 

On 1º Session

ShowMessage(TSystem.LoggedUser.User.Name);

Also shows 'User 2'

 

Thank you!