LeftoverLink – SwiftUI Prototype

LeftoverLink is a SwiftUI prototype designed to demonstrate a polished food‑sharing app for students. This version runs entirely in memory without any network or Firebase dependencies. It implements a clean MVVM architecture with a protocol‑based repository, a mock data source, and a modern, colourful user interface inspired by real apps.

Features

• Seeded Listings – On first launch the app loads five sample posts with a variety of dietary tags and locations so the listings tab feels alive.
• Listings Tab – Browse available food posts in a list of rounded cards. Each card shows the title, a short description, a coloured location badge and dietary tags styled as coloured pills. Pull to refresh re‑emits the current data. Swipe left to delete a listing.
• Search & Filter – Use the search bar to find posts by title or description. A horizontal filter bar at the top lets you narrow results by diet (Vegetarian, Vegan, Gluten‑Free, Nut‑Free). Select “All” to clear the filter.
• Add New Post – The second tab hosts a form to add a listing. Enter a title, description and location, select dietary tags with coloured pill buttons, and optionally choose an image via the PhotosPicker. The save button uses a green‑to‑blue gradient and is disabled until required fields are filled.
• Detail View – Tapping a card shows a full page with a larger image placeholder, the coloured location badge, dietary pills, description and a relative “Posted X ago” timestamp.
• MVVM Architecture – A ListingRepository protocol defines the interface for data operations. MockListingRepository uses a CurrentValueSubject to store listings in memory and seeds sample data. The ListingListViewModel combines repository data with search text and tag filters to produce the UI’s list.
• Extensible Design – You can swap out the mock repository for a real backend later by conforming to ListingRepository. Persistence, authentication or network calls can be added without touching the UI.

Project Structure

LeftoverLink/
  LeftoverLinkApp.swift       // App entry point, injects view model
  Models/
    FoodListing.swift         // Data model with title, description, location, tags, imageData, timestamp
  Protocols/
    ListingRepository.swift    // Repository protocol abstraction
  Repositories/
    MockListingRepository.swift // In‑memory repository with seeded sample data
  ViewModels/
    ListingListViewModel.swift  // View model with search & filter logic
  Views/
    ContentView.swift          // Tab view with listings and add views
    ListingsView.swift         // List with search, filter bar, pull to refresh, delete
    ListingRowView.swift       // Card style row for listings
    ListingDetailView.swift    // Full detail page
    AddListingView.swift       // Form for creating new posts
    TagFilterBar.swift         // Horizontal bar of dietary filter pills
  Helpers/
    TimeAgo.swift             // Utility to compute relative timestamps
    ImagePicker.swift         // UIKit image picker wrapper (unused in this version but included for reference)
  README.md                  // This file

Running the App

1. Open LeftoverLink.xcodeproj (or create a new SwiftUI iOS project and copy this directory into it). The project requires Xcode 15+ and iOS 17+.
2. Select an iOS simulator (e.g. iPhone 15 Pro) and press ⌘R to run.
3. On launch you will see five seeded posts. Use the search bar and filter pills to explore. Add new posts from the New Post tab and observe them appear at the top of the list. Swipe left on a row to delete.