add-guard

name	add-guard
description	Create and apply route guards in Modugo to protect routes with conditional logic

Add a Guard in Modugo

Guards implement IGuard and decide whether navigation to a route should proceed or redirect.

Create a guard

final class AuthGuard implements IGuard {
  @override
  FutureOr<String?> canActivate(BuildContext context, GoRouterState state) {
    final auth = Modugo.i.get<AuthService>();

    if (auth.isAuthenticated) return null; // allow navigation

    return '/login'; // redirect
  }
}

• Return null to allow navigation
• Return a route path (String) to redirect
• The method can be async (Future<String?>)

Apply a guard to a route

child(
  '/dashboard',
  builder: (_, _) => const DashboardPage(),
  guards: [AuthGuard()],
)

Apply a guard to an entire module

Guards on module() propagate automatically to every route inside the module.

module(
  '/admin',
  AdminModule(),
  guards: [AuthGuard(), AdminRoleGuard()],
)

Multiple guards

Guards are evaluated in order. The first one that returns a non-null path stops the chain.

guards: [AuthGuard(), FeatureFlagGuard('admin-panel')]

Guard with async logic

final class SessionGuard implements IGuard {
  @override
  Future<String?> canActivate(BuildContext context, GoRouterState state) async {
    final session = await Modugo.i.get<SessionService>().validate();

    return session.isValid ? null : '/session-expired';
  }
}

Notes

• Guards receive the BuildContext and GoRouterState — access DI via Modugo.i.get<T>() or context.read<T>()
• Exceptions thrown inside canActivate are caught, logged, and rethrown — the navigation is blocked
• Propagation: a guard on a module() route applies to all ChildRoute descendants automatically