showOnce property

String? showOnce
final

Shows this hint only the first time, ever, under this key.

The key is recorded in HintRegistry.storage as the bubble opens, and every later attempt to show it — by trigger, by controller, by HintTrigger.onAppear — does nothing. This is the "new feature" callout that must not nag:

Hint(
  showOnce: 'payslip-tip',
  triggers: const <HintTrigger>{HintTrigger.onAppear},
  message: 'Payslips live here now',
  child: payslipTab,
)

The default storage forgets on restart; point HintRegistry.storage at real persistence to make it stick, and use HintRegistry.resetShowOnce to let a hint appear again.

Reading the flag is asynchronous, so a hint that is already open when the answer arrives is left alone: the guard applies to opening, never to closing something the user is reading.

Implementation

final String? showOnce;