homelabby/.planning/phases/04-usb-manager-label-printing/04-05-SUMMARY.md

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
04-usb-manager-label-printing	05	frontend	usb sse react label-printing real-time	requires provides affects 04-03 USB-04-frontend DashboardPage ItemCard ItemRow	added patterns EventSource SSE react-hot-toast lucide-react icons	created modified web/src/hooks/useUSBEvents.ts web/src/components/USBStatusBar.tsx web/src/lib/api.ts web/src/components/inventory/ItemCard.tsx web/src/components/inventory/ItemRow.tsx web/src/pages/DashboardPage.tsx	Print button added to ItemCard and ItemRow directly (not DashboardPage map) — cleaner separation of concerns handlePrintLabel defined at module level outside component to avoid per-render allocation USBStatusBar placed in DashboardPage header (flex justify-between alongside title) No ESLint config exists in project — skipped ESLint step, TypeScript + build used as verification	duration completed tasks_completed files_changed 8m 2026-04-10 2 6

Phase 04 Plan 05: Frontend USB Status Bar and Print Label Summary

One-liner: SSE-backed useUSBEvents hook with USBStatusBar component and per-item print label button wired to POST /api/labels/:id/print with react-hot-toast feedback.

Tasks Completed

Task	Description	Commit
1	useUSBEvents hook + USBStatusBar component	8b88970
2	Wire USBStatusBar + Print Label into dashboard	3de1e4f

What Was Built

useUSBEvents hook (web/src/hooks/useUSBEvents.ts)

• Subscribes to GET /api/usb/events SSE stream via new EventSource('/api/usb/events')
• Maintains connectedDevices: Map<string, DeviceSpec> in React state
• Connect events add to map; disconnect events remove from map
• Malformed JSON silently ignored (T-04-14 mitigated)
• EventSource auto-reconnects on error (T-04-15 accepted)
• Exports: useUSBEvents, DeviceEvent, DeviceSpec, StateConnected, StateDisconnected

USBStatusBar component (web/src/components/USBStatusBar.tsx)

• Consumes useUSBEvents(), renders connected device list
• Role icons: Printer (role=0), Cable (role=1), Usb (role=2/unknown)
• Green dot per connected device with device name
• Empty state: "No USB devices" with USB icon in muted text
• ClickHouse design: black bg, border-white/10, text-white/80, bg-green-500 status dots

api.ts additions (web/src/lib/api.ts)

• printLabel(deviceId: number): Promise<PrintLabelResponse> — POST /api/labels/:id/print
• PrintLabelResponse interface: { status: string; print_skipped?: boolean }
• Throws typed Error on non-OK response

ItemCard (web/src/components/inventory/ItemCard.tsx)

• Module-level handlePrintLabel(e, itemId) using printLabel() from api.ts
• Printer icon button in CardFooter alongside NetBox link
• Toast: loading → success / "queued — printer not connected" / error

ItemRow (web/src/components/inventory/ItemRow.tsx)

• Same handlePrintLabel pattern
• Print button added to quick-actions group (appears on hover with ExternalLink)
• Opacity transition matches existing group-hover pattern

DashboardPage (web/src/pages/DashboardPage.tsx)

• Imports and renders <USBStatusBar /> in page header (flex row, right-aligned)
• No layout restructuring — additive change only

Deviations from Plan

Auto-fixed Issues

None — plan executed exactly as written with one minor deviation:

1. [Rule 2 - Deviation] Print button added to ItemCard/ItemRow rather than DashboardPage map

• Found during: Task 2
• Reason: DashboardPage passes items to <ItemCard> and <ItemRow> as components — adding print logic inline in the map would duplicate code and break component encapsulation. Plan said "find where item quick actions are rendered" which is the card/row components.
• Impact: Cleaner architecture; identical user-visible result
• Files modified: ItemCard.tsx, ItemRow.tsx (instead of DashboardPage.tsx map)

Known Stubs

None — all data flows wired. USBStatusBar connects to live SSE. Print button calls real endpoint.

Threat Flags

None — no new trust boundaries beyond those in the plan's threat model.

Self-Check

Files exist:

• web/src/hooks/useUSBEvents.ts — FOUND
• web/src/components/USBStatusBar.tsx — FOUND
• web/src/lib/api.ts (modified) — FOUND
• web/src/components/inventory/ItemCard.tsx (modified) — FOUND
• web/src/components/inventory/ItemRow.tsx (modified) — FOUND
• web/src/pages/DashboardPage.tsx (modified) — FOUND

Commits:

• 8b88970 — feat(04-05): add useUSBEvents hook and USBStatusBar component
• 3de1e4f — feat(04-05): wire USBStatusBar and Print Label button into dashboard

Build: npm run build — PASSED (tsc -b + vite build, 0 errors, 1965 modules)

Self-Check: PASSED