Implement validator not requiring ControlToValidate.

[sergeymorkovkin]

Sometimes there may be validations when there are no input controls on a page and it's still required to use custom validation (OnServerValidate?). Alternatively, you can make ControlToValidate? property of TCustomValidator optional.

Here is a short example:

- User enters database access information, clicks 'Next'. - System validates input and attempts to connect to MySQL.

In this case connection failure message must not be bound to any input fields and should be displayed above the entire form.