Sprint 3 - Moviles-G45/FlutterApp GitHub Wiki

🧩 Sprint 3 - Deliverables

🚀 Functionalities and Design Details

📌 a. Features Delivered

1. 📍 Geofencing Purchase Reminder

Description:
This feature automatically detects when a user is near a shopping mall or commercial center and sends a personalized push notification reminding them to log any recent purchases. The notification acts as a real-time prompt, helping users maintain accurate expense tracking and stay within their budget goals.

Example Notification:

🛍️ "You're near Parque La Colina Mall — Did you spend on food or shopping? Log your transaction now to stay on budget!"

Context Awareness:

  • The app uses geolocation services to determine proximity (~150 meters) to a curated list of over 20 major shopping malls in Bogotá.
  • When detected near a mall, a notification is triggered with relevant context.

2. 🌙 Weekend Night Spending Reminder

Description:
Detects weekend nights (Friday–Saturday after 8 PM) and sends a notification alert to help users control entertainment spending.

📈 Business Questions (BQs)

Member Business Question Sprint
Gabriela How many consecutive months has the user successfully stayed within their monthly spending limit? Sprint 2
Juanda Obando Which expense categories has the user exceeded their allocated budget for this month, and by what percentage? Sprint 2
Juanda Castillo Which are the categories of type ‘needs’ in which the users spend the most? Sprint 2
Santiago What are the months in which the users spend the most? Sprint 2
Miguel How many consecutive months has the user successfully stayed within a fixed monthly spending limit? Sprint 2
Julian How many days have passed since the last record of expenses of a user? Sprint 2
Gabriela How much has the user contributed to a saving goal this month? Sprint 3
Juanda Obando Which are the categories of type needs in which the users spend the most? Sprint 3
Juanda Castillo How many users have an average daily expenditure between <50, 50 - 150, >150? Sprint 3
Santiago Which are the categories of type ‘savings’ in which the users spend the most? Sprint 3
Miguel Which are the categories of type ‘wants’ in which the users spend the most? Sprint 3
Julian What are the months in which the users spend the most? Sprint 3

🔗 Eventual Connectivity Strategies

🗂️ Local Storage Strategies

  • Authentication and Recovery Without Internet:

    • Tokens and Credentials: Securely store user tokens and credentials in iOS Keychain after successful authentication.
    • Localized Messages: Preload and store OS-specific error messages locally to ensure availability offline.

  • Main Screen Without Internet:

    • Use of SharedPreferences to cache monthly balance and expenses, ensuring immediate offline access.
    • Supports an offline-first strategy for reliability even during disconnections.

  • Transactions Without Internet:

    • Transaction Queue: Persist offline-initiated transactions in durable local storage (Core Data/SQLite) to sync once reconnected.
    • Data Security: Implement encryption or verification mechanisms to protect stored transactions.

🧠 Multi-threading Strategies

Smart Multithreading Strategy

To ensure smooth performance, especially with multiple geofenced malls, the proximity detection algorithm is offloaded to a background thread using Dart’s Isolate.

How It Works:

  • Every 5 minutes, the app checks the user’s GPS location.
  • A separate Isolate compares the user’s location to mall coordinates.
  • Reduces CPU load on the main thread, improves UI responsiveness, and saves battery.
  • When proximity is confirmed, the Isolate sends back the mall’s name, triggering a notification.

🧹 Caching Strategies

  • Main Screen Caching:
    • Uses the shared_preferences package to cache essential data like balance and expenses.
    • If the user loses connection, cached data ensures seamless display of financial information.
    • Upon reconnection, the app refreshes the data from the backend, keeping the cache updated.

🎥 Ethics Reflection Video