Application Features Overview - iOS Implementation

Local Storage

FileManager

• Purpose: Stores temporary image attachments for notifications.
• Benefit: Efficiently manages local file storage for notification images and attachments.

UserDefaults

• Purpose: Stores notified offer IDs to prevent duplicate notifications.
• Benefit: Provides lightweight persistence for tracking user interactions with offers.

Firestore Offline Persistence

• Purpose: Caches Firestore data for offline access.
• Benefit: Ensures data availability even when network connectivity is limited.

Multi-Threading

OperationQueue

• Context: Implemented in OffersDistanceOperation.
• Purpose: Handles CPU-intensive distance calculations between user location and offers.
• Benefit: Prevents UI blocking during complex calculations by running them in background threads.

Async/Await Operations

• Context: Used in DataService for network operations.
• Purpose: Manages asynchronous Firestore operations and data processing.
• Benefit: Provides clean, modern concurrency handling with improved error management.

Background Tasks

• LocationManager: Monitors user location changes in the background.
• ProximityTimer: Checks nearby offers every 20 seconds.
• Benefit: Maintains real-time location awareness without impacting app performance.

Caching

NSCache

• Context: Implemented in EnhancedDataService.
• Purpose: Caches fetched offers to reduce database queries.
• Benefit: Improves performance and reduces network usage by storing frequently accessed data.

Location Data Buffering

• Context: Used in location updates processing.
• Purpose: Implements debounce mechanism for location updates.
• Benefit: Prevents excessive processing of rapid location changes.

Eventual Connectivity

Firebase Offline Support

• Purpose: Handles database operations during network interruptions.
• Benefit: Ensures app functionality continues during connectivity issues.

Background Operations

• Purpose: Manages offer notifications and calculations during poor connectivity.
• Benefit: Maintains core functionality even with unstable network conditions.