Label Node

[MaddieWright]

What?

Implemented the Label Node. A terminal pipeline node that lets users mark and name time-windowed events during EEG streaming sessions.

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How?

Frontend (label-node, label-combo-box, label-timeline-panel):

• Trigger button starts/stops a labeled time window using live backend EEG timestamps (rawTime) to avoid UTC/local timezone drift
• Label popup with name input and color picker; duplicate label names are blocked with an inline error
• Timeline view: filled, lane-packed bars showing all labeled events on a scrollable horizontal axis
• Graph view: Recharts LineChart with a numeric timeMs XAxis; teal ReferenceArea highlights the selected event's time range; fetches event EEG data via the CSV export endpoint
• Labels persist across page reloads -> saved to and loaded from activeSessionId on mount
• Right-side output handle removed -> label node is end-of-pipeline only (no downstream connections)
• Sub-millisecond (nanosecond) timestamp truncation added to all timestamp parsers for backend compatibility

Backend:

• New /api/sessions/:id/time-label GET/POST routes for reading and writing time labels
• New /api/sessions/:id/eeg_data/export POST route returning CSV with optional start_time/end_time filtering
• DB migrations for time_labels table and session-scoped EEG data
• Reordered migrations to fix ordering conflict; fixed label session name uniqueness; added sqlx offline cache

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Testing

• Triggered labels during live streaming; verified start/end timestamps stored correctly
• Timeline bars render with correct positions and lane-packing for overlapping events
• Graph view jumps to event data and shows teal highlight over the correct time range
• Labels reload on page refresh and when switching sessions
• Duplicate label names are blocked with inline error
• No node can be connected after the label node

[github-actions]

❌ PR approval conditions NOT satisfied. At least 1 team lead OR 2 team members must approve before merging.
[Last checked: 2026-04-12T02:02:11.575Z]