TJvLoginDialog usage??

[Ian Branch 127]

Hi Guys,  in particular JVCL Gurus,

I am playing with the JvLoginDialog.  It runs immediately the App is started and seemingly before the application's Form is created.

I want to use it to verify the log in details of a user from a database table.

Unfortunately the database bits are on the Form, engine, session, connection, table, and as a result they are not seen when the component's  OnCheckUser event fires. :-(

Naturally I can't find any documented Help for the component.

Can anybody advise how to achieve what I am trying to do or can't I?

Regards & TIA,

Ian

 

 

[rvk 33]

4 hours ago, Ian Branch said:

It runs immediately the App is started and seemingly before the application's Form is created.

That depends on where you put the TJvLoginDialog.

 

If you have a DataModule, ideally the TJvLoginDialog goes on the TDataModule and you'll execute it in the DataModuleCreate() after connecting to the TDatabase. Set Active to false at designtime so you can do this yourself in the DataModuleCreate().

Login.Active := true;
if not Login.Execute then
begin
  // inform the user and exit
  Application.Terminate;
end;

 

In the OnCheckUser you can check the database if the user has entered valid credentials.

 

If you have the TDatabase component on a TForm and you initialize it there, then you'll need to put the TJvLoginDialog there too (in FormCreate() and after the initialization of the TDatabase-component).

[Ian Branch 127]

Ahh Excellent.  Tks RVK.

Is there a mechanism to use the AttemptNumber is it just a place holder?

 

Regards & Tks,

Ian

[rvk 33]

Looking at the source, each time you press the OK button a private variable FAttempt is increased. When it goes over the AttemptNumber a Cancel is automatically triggered. So the Login will fail.

 

procedure TJvLoginForm.OkBtnClick(Sender: TObject);
begin
  Inc(FAttempt);
  if Assigned(FOnOkClick) then
    FOnOkClick(Self)
  else
    ModalResult := mrOk;
  if (ModalResult <> mrOk) and (FAttempt >= AttemptNumber) then
    ModalResult := mrCancel;
end;

 

[Ian Branch 127]

Hi RVK,

Ahh.  I see.  And I have determined that setting 'AllowLogin' in the CheckUser procedure to false is what to manage the count.

I think I have all that I need now.

Tks.

Regards,

Ian