---
phase: 04-frontend
plan: 02
subsystem: ui
tags: [react, typescript, app-tsx, alert-banner, admin-monitoring]

# Dependency graph
requires:
  - phase: 04-frontend
    plan: 01
    provides: "AlertBanner component, AdminMonitoringDashboard component, AlertEvent type, adminService.getAlerts/acknowledgeAlert"
provides:
  - "Dashboard with AlertBanner above nav wired to adminService.getAlerts"
  - "Monitoring tab replaced with AdminMonitoringDashboard"
  - "Optimistic alert acknowledge with re-fetch fallback"
affects: []

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Optimistic UI: filter local state immediately on acknowledge, re-fetch on API failure"
    - "Admin-gated data fetching: isAdmin dependency in useEffect prevents unnecessary API calls"
    - "AlertBanner above nav: conditional render before <nav> so banner shows on all tabs"

key-files:
  created: []
  modified:
    - frontend/src/App.tsx

key-decisions:
  - "AlertBanner placed before <nav> element so it shows across all tabs, not scoped to monitoring tab"
  - "handleAcknowledge uses optimistic update (filter state immediately) with re-fetch on failure"
  - "Alert fetch gated by isAdmin — non-admin users never trigger getAlerts API call"
  - "UploadMonitoringDashboard import removed entirely — replaced by AdminMonitoringDashboard"

requirements-completed:
  - ALRT-03
  - ANLY-02
  - HLTH-01

# Metrics
duration: 2min
completed: 2026-02-24
---

# Phase 04 Plan 02: Wire AlertBanner and AdminMonitoringDashboard into App.tsx Summary

**AlertBanner wired above navigation in Dashboard with optimistic acknowledge, AdminMonitoringDashboard replacing UploadMonitoringDashboard in monitoring tab**

## Performance

- **Duration:** ~2 min
- **Started:** 2026-02-24T21:37:58Z
- **Completed:** 2026-02-24T21:39:36Z
- **Tasks:** 1 auto + 1 checkpoint (pending visual verification)
- **Files modified:** 1

## Accomplishments

- Added `AlertBanner` and `AdminMonitoringDashboard` imports to `frontend/src/App.tsx`
- Added `AlertEvent` type import from `adminService`
- Added `activeAlerts` state (AlertEvent[]) inside Dashboard component
- Added `useEffect` gated by `isAdmin` to fetch alerts on mount
- Added `handleAcknowledge` callback with optimistic update (immediate filter) and re-fetch on failure
- Rendered `AlertBanner` above `<nav>` so it appears on all tabs when admin has active alerts
- Replaced `UploadMonitoringDashboard` with `AdminMonitoringDashboard` in monitoring tab
- Removed unused `UploadMonitoringDashboard` import
- `npx tsc --noEmit` passes with zero errors
- `npm run build` succeeds

## Task Commits

Each task was committed atomically:

1. **Task 1: Wire AlertBanner and AdminMonitoringDashboard into Dashboard** - `6c345a6` (feat)

## Files Created/Modified

- `frontend/src/App.tsx` - Added AlertBanner above nav, added alert state and optimistic acknowledge, replaced UploadMonitoringDashboard with AdminMonitoringDashboard in monitoring tab

## Decisions Made

- AlertBanner is placed before the `<nav>` element (not inside a tab) so it appears globally on every tab when the admin has active critical alerts
- Optimistic update pattern: `setActiveAlerts(prev => prev.filter(a => a.id !== id))` fires before the API call, restoring state on failure via re-fetch
- Alert fetch is fully gated on `isAdmin` in the `useEffect` dependency array — non-admin users never call `adminService.getAlerts()`
- `UploadMonitoringDashboard` import was removed entirely since AdminMonitoringDashboard replaces it

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None.

## User Setup Required

Task 2 is a `checkpoint:human-verify` — admin must visually verify the monitoring tab and alert banner in the running application.

## Next Phase Readiness

- Phase 4 is complete pending human visual verification (Task 2 checkpoint)
- All requirements ALRT-03, ANLY-02, HLTH-01 are now fully implemented frontend-to-backend

## Self-Check: PASSED

- `04-02-SUMMARY.md` exists at `.planning/phases/04-frontend/04-02-SUMMARY.md`
- `frontend/src/App.tsx` exists and modified
- Commit `6c345a6` exists in git log

---
*Phase: 04-frontend*
*Completed: 2026-02-24*