Scadoo — Edward Attuati

// 01 — overview

Why Scadoo exists

The project was born from a daily problem: food expiring unseen, forgotten shopping lists, and no simple way to track how many boxes of pasta are left in the pantry. Existing apps either charge a subscription or have cluttered interfaces.

Scadoo's goal is to do a few things, do them well, and do them fast: scan a product, the app fetches name and brand from Open Food Facts, add the expiry date and you're done. Two taps. Fully offline.

The shopping list is designed for family use: one button shares the list via WhatsApp or iMessage, formatted cleanly and ready to use at the supermarket.

// 02 — features

What the app does

📷

Quick Scan

Scan barcode → API lookup → pre-filled form. Product in pantry in 2 taps.

🌐

Open Food Facts

Italian endpoint first, then worldwide fallback. Fetches name, brand, category, image.

⏱️

Expiry Tracking

Color coding: green (ok) → yellow (7 days) → orange (3 days) → red (expired).

📦

Separate Locations

Fridge, Pantry and Freezer — filterable from the inventory screen.

🔔

Smart Notifications

Daily digest at 9:00 AM with expiry summary. No server required.

🛒

Shopping List

Check, reorder, add manually. Share via Share Sheet in one tap.

➕

Quantity Control

+/− directly on the card. Quantity hits 0 → product removed automatically.

📴

Offline-first

Everything on local SQLite. Works without connection. API is optional.

// 03 — architecture

Code structure

The code is organized in layers with clear responsibilities. Each layer depends only on the one below.

lib/ ├── main.dart ← init, Provider setup, bottom nav ├── theme/ │ └── app_theme.dart ← colors, typography, expiryColor() ├── models/ ← pure data, no Flutter dependency │ ├── product.dart ← daysToExpiry, isExpired, toMap/fromMap │ └── shopping_item.dart ├── services/ ← I/O, network, system — no UI │ ├── database_service.dart ← SQLite singleton, CRUD │ ├── notification_service.dart ← schedule, daily digest │ └── openfoodfacts_service.dart ├── providers/ ← global state, calls services, notifies UI │ ├── inventory_provider.dart │ └── shopping_list_provider.dart ├── screens/ ← one screen = one file │ ├── home_screen.dart │ ├── inventory_screen.dart │ ├── scanner_screen.dart │ ├── add_product_screen.dart │ └── shopping_list_screen.dart └── widgets/ └── product_card.dart ← swipe, quantity control, expiry badge

// 04 — tech stack

Dependencies & Rationale

📷

mobile_scanner

Best-performing barcode scanner for Flutter. Handles focus, torch, and custom overlay via CustomPainter.

🗄️

sqflite + path

Native SQLite, 100% offline. No cloud required. Two tables: products and shopping_items.

🔔

flutter_local_notifications

Locally scheduled notifications without server. Daily digest at 9:00 AM + immediate on open.

🌐

http

REST calls to Open Food Facts API. Italian endpoint first, then worldwide fallback.

🧩

provider

ChangeNotifier for InventoryProvider and ShoppingListProvider. Simple, readable, no codegen.

↔️

flutter_slidable

Swipe-to-delete and swipe-to-edit on product cards. Native mobile UX.

📤

share_plus

Share shopping list via OS share sheet (WhatsApp, iMessage, etc.) without backend.

🆔

uuid

Unique IDs for products and shopping items. Prevents collisions in SQLite.

// 05 — key code

Expiry logic in the model

Expiry logic is encapsulated directly in the model, with no Flutter dependencies. Easy to test and reuse.

Dart lib/models/product.dart

class Product {
  final DateTime? expiryDate;

  int get daysToExpiry {
    if (expiryDate == null) return 9999;
    final today = DateTime(DateTime.now().year, DateTime.now().month, DateTime.now().day);
    final expiry = DateTime(expiryDate!.year, expiryDate!.month, expiryDate!.day);
    return expiry.difference(today).inDays;
  }

  bool get isExpired          => expiryDate != null && daysToExpiry < 0;
  bool get isExpiringSoon     => expiryDate != null && daysToExpiry <= 3;
  bool get isExpiringThisWeek => expiryDate != null && daysToExpiry <= 7;
}

Open Food Facts Integration

The service tries the Italian endpoint first (more complete local products), then falls back to worldwide. The response is normalized into an OpenFoodFactsResult object independent of the API JSON.

Dart lib/services/openfoodfacts_service.dart

Future<OpenFoodFactsResult> fetchProduct(String barcode) async {
  for (final base in [
    'https://it.openfoodfacts.org',
    'https://world.openfoodfacts.org',
  ]) {
    final result = await _fetch('$base/api/v0/product/$barcode.json');
    if (result.found) return result;
  }
  return const OpenFoodFactsResult(found: false);
}

// 06 — challenges

Problems encountered

Click each problem to see the solution adopted.

Accidental double scan from barcode scanner▼

The onDetect callback is called multiple times for the same barcode in milliseconds. Solution: boolean flag _processing that blocks subsequent callbacks until navigation completes.

Expiry day calculation: timezone and midnight▼

Using DateTime.now().difference(expiryDate) in hours can give wrong results near midnight. Solution: normalize both dates to DateTime(year, month, day) before calculating the difference in whole days.

Open Food Facts: variable quality of Italian data▼

Many Italian products have product_name in English or empty. Solution: fallback cascade — product_name_it → product_name → generic_name_it → generic_name. If all empty, the barcode is shown and the user enters the name manually.

Notifications: recalculate after every pantry change▼

Every add, edit or delete requires recalculating scheduled notifications. Solution: cancelAll() + reschedule inside loadProducts() of the provider, so the cycle is automatic.

SQLite on Flutter: database path between iOS and Android▼

Database path differs between iOS and Android. Solution: use sqflite's getDatabasesPath() combined with path.join() to build the correct path on both platforms.

// 07 — roadmap

Progress

Progress 11 / 15 completed

✓Architecture models / services / providers / screensDone

✓Barcode scanner with mobile_scannerDone

✓Open Food Facts integration (IT + World endpoint)Done

✓Local SQLite database with full CRUDDone

✓Local push notifications (immediate + daily digest)Done

✓Shopping list with Share Sheet sharingDone

✓Location filter (Fridge / Pantry / Freezer)Done

✓Duplicate barcode detection + manual entryDone

✓100+ Italian product categories (Open Food Facts)Done

✓Add to pantry directly from shopping listDone

✓Price history with min / max / average statisticsDone

○iOS home screen widget with upcoming expiriesNext

○Waste statistics: food expired per monthNext

○Recipe suggestions based on expiring productsNext

○App Store release (iOS only)Next