InventoryManager (Scanventory)

InventoryManager is a modern iOS app built with SwiftUI that allows users to scan QR codes, manage them via a local Core Data database, and seamlessly sync results to Google Sheets.
It also includes a flexible settings system where scanning rules, parsing delimiters, and spreadsheet destinations can be customized.

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Functionalities

• Live QR Code Scanning using AVFoundation
• Photo Picker — decode QR codes from existing images
• Google Sheets Integration via Google APIs (Sheets, Drive, Auth)
• Offline-first persistence with Core Data
• Customizable settings
  • Spreadsheet selection
  • Scanning behavior (e.g. result screen on/off, auto-save)
  • QR code parsing rules (delimiter, acceptance text)
• Developer-friendly UX
• Toast notifications
• Loading overlays with animated SF Symbols
• Modern SwiftUI design, edge-to-edge gradients

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Architecture Overview

The project is structured according to MVVM + Services + Protocol-oriented DI:

Folder Structure

• Constants — app-wide constants (colors, Google keys, UserDefaults keys)
• Errors — strongly-typed error enums (GoogleAuthError, QrCodeError, etc.)
• Model — core data models & domain entities (GoogleSpreadsheet, QRCodeResult)
• Protocols — dependency injection boundaries (QRScanning, SelectionProvider, DatabaseProvider, etc.)
• Services
  • GoogleServices — authentication & spreadsheets API
  • QRScannerService — wraps AVFoundation camera session
  • DatabaseService — Core Data persistence
  • SelectionService — manages user spreadsheet/sheet selections
• ViewModels — one per feature screen (ScannerViewModel, ScanHistoryViewModel, SettingsViewModel, etc.)
• Views
  • Scanning — camera preview, stream, picker
  • History — scan history, detail view
  • Settings — QR code settings, scan settings, spreadsheet settings
• ViewComponents — reusable SwiftUI components (cards, toasts, loading overlay)

Design Patterns & Methodologies

• MVVM — clear separation of concerns between View, ViewModel, and Service
• Dependency Injection — all services are injected via protocols (QRScanning, GoogleSpreadsheetWriter, etc.)
• Protocol-Oriented Programming — abstractions for persistence, scanning, and settings
• Single Source of Truth — state stored in ViewModels or SettingsStores, published via Combine
• Environment Objects — propagate shared stores across the view hierarchy
• Async/Await + Combine — modern concurrency & reactive pipelines

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iOS Concepts Used

• SwiftUI-first architecture
  • NavigationStack, .sheet(item:), .alert(item:)
  • @StateObject, @EnvironmentObject, @ObservedObject
• Structured Concurrency
  • async/await, Task, withCheckedThrowingContinuation
• Combine Interop
  • Service publishers bridged into @Published ViewModel state
• Core Data
  • @FetchRequest, data grouping by date for history
• AppStorage
  • lightweight UserDefaults integration for settings
• Protocol-driven testing
  • mock implementations of QRScanning, GoogleSheetWriting, QRCodeSettingsProviding
• UI Polish
  • SF Symbols with .symbolEffect()
  • Animated Toasts and Loading overlays
  • Safe area–aware buttons & layouts

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Testability

• ViewModels are tested by injecting fake services (e.g., FakeQRScannerService).
• Pure parsing functions for QR logic (delimiter, acceptance text) allow unit testing without UI.
• Mock persistence and settings stores enable snapshot-style testing of app flows.

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License

MIT