Role Switch Widget state cascade and confirmation
epic-role-based-access-control-ui-and-navigation-task-007 — Implement the state update flow triggered by the Role Switch Widget: dispatch role change event to Role State Manager, show brief loading indicator during transition, confirm new active role via snackbar or visual indicator, and ensure the home screen and bottom navigation re-render for the new role without full app restart.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 2 - 518 tasks
Can start after Tier 1 completes
Implementation Notes
Use BlocListener (not BlocBuilder) for side effects like SnackBar and loading overlay — BlocBuilder only for widget tree reconstruction. Wrap the loading indicator in an IgnorePointer to prevent accidental taps during transition. The SnackBar should use ScaffoldMessenger.of(context).showSnackBar() to avoid context issues. Ensure the Role State Manager BLoC is provided at a high enough level in the widget tree (e.g.
MaterialApp level or above the Navigator) so both HomeScreen and RoleAwareBottomNav rebuild from the same state. Use equatable on BLoC states to prevent duplicate emissions. For Riverpod users: use a StateNotifier and watch the provider at the relevant widget level.
Testing Requirements
Write BLoC unit tests: (1) assert RoleChangedEvent transitions state to RoleLoadingState then RoleActiveState, (2) assert error event transitions to RoleErrorState with previous role preserved. Widget tests: (1) mock BLoC and verify SnackBar appears after state emission, (2) verify loading indicator shown during RoleLoadingState, (3) verify home screen rebuilds with correct role variant after RoleActiveState. Integration test: select role, assert full UI update cycle completes. Test edge case: selecting the already-active role produces no state change.
Target 85% branch coverage on state transition logic.
Combining GoRouter's declarative redirect logic in the route guard with StatefulShellRoute's stateful branch management is known to produce subtle bugs where the shell rebuilds unnecessarily on role switches, losing tab state or causing double-navigation events.
Mitigation & Contingency
Mitigation: Implement the route guard as a GoRouter redirect callback that only evaluates role from an already-resolved Riverpod provider (not async). Use a dedicated ShellRoute navigator key per tab branch to anchor state independently of role-driven rebuilds. Write integration tests for the full navigation graph.
Contingency: If StatefulShellRoute state loss is confirmed during QA, fall back to a manual tab state preservation approach using a TabStateManager service that caches the last route per tab and restores it after role switches, decoupling tab state from the shell lifecycle.
The role-based home screen must render three significantly different layouts (coordinator dashboard, peer mentor activity summary, org admin overview). If these variants are implemented as a single widget with conditionals, the file will become unmaintainable and difficult to test in isolation, especially as each variant grows with downstream feature additions.
Mitigation & Contingency
Mitigation: Design the role-based home screen as a router/dispatcher widget that delegates to three separate variant widgets (CoordinatorHomeView, PeerMentorHomeView, OrgAdminHomeView). Each variant is independently testable and can be developed by separate team members in parallel.
Contingency: If variant coupling has already occurred before this risk is addressed, refactor to the dispatcher pattern in a dedicated cleanup task before feature handoff. The dispatcher pattern is a straightforward extraction that carries low refactoring risk.
The no-access screen must link global admin users to the correct admin portal URL, which may differ per organization (NHF, HLF, Blindeforbundet each have their own admin portals). Hardcoding a single URL will result in wrong or broken links for some global admin users.
Mitigation & Contingency
Mitigation: Source the admin portal URL from the organization's configuration record in Supabase rather than hardcoding it. The no-access screen reads the active org context and resolves the portal URL dynamically. Provide a safe fallback to a generic Norse Digital Products support page if the URL is not configured.
Contingency: If dynamic URL resolution is not ready when the no-access screen ships, display a static instruction to contact the organization's administrator along with a support email address as an interim measure, and track the URL configuration task as a follow-up.