studysprint/notes/work-report-2026-04-22.md

#Overview

Implemented a full local notification system for assignment deadlines using Expo Notifications, integrated with Supabase-backed assignment data.

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#CoreFeatures

#LocalNotifications

• Integrated expo-notifications for scheduling local device notifications

• Configured notification handler for:

  • banner display
  • sound
  • badge updates

• Notifications trigger even when:

  • app is in background
  • app is fully closed

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#DeadlineReminderLogic

• Implemented reminder scheduling based on assignment deadlines

• Default behavior:

  • notify 24 hours before deadline

• Prevented invalid scheduling:

  • skip if reminder time is in the past
  • validate deadline input before scheduling

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#AssignmentIntegration

• Notifications tied directly to assignment lifecycle:

On Create:

• Insert assignment into Supabase
• Retrieve inserted assignment (aId)
• Schedule reminder if not completed

On Edit:

• Cancel existing scheduled notification
• Update assignment in Supabase
• Schedule new reminder if still active

On Delete:

• Cancel scheduled notification
• Remove stored notification reference

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#NotificationPersistence

• Stored notification IDs locally using AsyncStorage

• Structure:

  • assignmentId → notificationId

• Enables:

  • precise cancellation
  • avoiding duplicate notifications

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#NotificationCancellation

• Implemented cancellation flow using:

  • Notifications.cancelScheduledNotificationAsync(notificationId)

• Ensures:

  • no duplicate reminders on edit
  • no orphan notifications after deletion

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#NotificationRouting

• Implemented navigation on notification tap

• Uses:

  • Notifications.addNotificationResponseReceivedListener
  • Notifications.getLastNotificationResponse()

Behavior:

• Works when:

  • app is open
  • app is in background
  • app is launched from notification

Routing:

• Extract aId from notification.content.data
• Navigate using Expo Router:

router.push({
  pathname: "/assignment/viewDetailsAssignment",
  params: { aId }
});

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#AuthIntegration

• Notification observer only runs when user session exists
• Prevents routing into protected screens when unauthenticated

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#ArchitectureDecisions

#LocalVsBackend

• Chose local notifications only

• No backend push notifications used

• Rationale:

  • single-user reminders
  • simpler implementation
  • no need for push tokens or server logic

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#DataSeparation

• Supabase:

  • stores assignment data (source of truth)

• Device (AsyncStorage):

  • stores notification IDs (device-specific state)

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#RoutingApproach

• Used existing static route:

  • /assignment/viewDetailsAssignment

• Passed aId via params instead of dynamic route [aId].tsx

• Keeps current structure intact

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#Summary

A complete local notification system has been implemented with:

• deadline-based scheduling
• lifecycle-aware updates (create/edit/delete)
• duplicate prevention
• device-level persistence
• deep-link style navigation on tap

This provides a solid, production-ready foundation for assignment reminders within the app.

Interesting sources: https://docs.expo.dev/versions/latest/sdk/async-storage/ https://docs.expo.dev/versions/latest/sdk/securestore/ https://docs.expo.dev/versions/latest/sdk/notifications/