beforeLeave property

Future<void> Function(VRedirector? vRedirector, void saveHistoryState(Map<String, String> state)) beforeLeave

Called when the route changes and the VRouteElement associated to this VWidgetGuard is in the previous route but not in the new one

Use vRedirector if you want to redirect or stop the navigation. DO NOT use VRouter methods to redirect. vRedirector also has information about the route you leave and the route you go to

Use newVRouteData if you want information on the new route but be careful, on the web newVRouteData is null when a user types a url manually

Use newVRouteData if you want information on the new route but be careful, on the web newVRouteData is null when a user types a url manually

saveHistoryState can be used to save a history state before leaving This history state will be restored if the user uses the back button You will find the saved history state in the VRouteElementData using VRouteElementData.of(context).historyState WARNING: Since the history state is saved in VRouteElementData, if you have multiple VWidgetGuards associated to the same VRouteElement, only one should use saveHistoryState.

Note that you should consider the navigation cycle to handle this precisely, see https://vrouter.dev/guide/Advanced/Navigation%20Control/The%20Navigation%20Cycle

Also see:

• VRouter.beforeLeave for global level beforeLeave
• VRouteElement.beforeLeave for route level beforeLeave
• VRedirector to known how to redirect and have access to route information

Implementation

final Future<void> Function(
  VRedirector? vRedirector,
  void Function(Map<String, String> state) saveHistoryState,
) beforeLeave;