Gym Tracker#

iOS app for tracking Virginia Tech gym occupancy and displaying campus events. Supports iOS, watchOS, and WidgetKit extensions.

GitHub · Tangled

Architecture#

Core Services#

GymService (GymService.swift)

• Singleton @MainActor class managing gym occupancy state
• Publishes @Published properties: mcComasOccupancy, warMemorialOccupancy, boulderingWallOccupancy
• Automatic refresh: 30-second interval when app is active (via UIApplication.didBecomeActiveNotification)
• Retry logic: 60-second delay if all fetches fail
• Uses GymOccupancyFetcher for data fetching

GymOccupancyFetcher (GymOccupancyFetcher.swift)

• Static enum performing HTTP requests
• Concurrent fetching: async let for parallel facility requests
• POST request to https://connect.recsports.vt.edu/FacilityOccupancy/GetFacilityData
• Request body: facilityId={uuid}&occupancyDisplayType={uuid} (URL-encoded)
• Response: HTML containing data-occupancy and data-remaining attributes
• Parsing: Delegates to OccupancyHTMLParser for regex extraction

OccupancyHTMLParser (OccupancyHTMLParser.swift)

• Regex-based HTML parsing (no external dependencies)
• Pattern: data-occupancy="([0-9]+)" and data-remaining="([0-9]+)"
• Extracts occupancy and remaining capacity integers from HTML response

EventsViewModel (EventsViewModel.swift)

• Fetches RSS feed from https://gobblerconnect.vt.edu/organization/www_recsports_vt_edu/events.rss
• XML parsing via XMLParser delegate pattern (RSSParser class)
• Caching: JSON file in app caches directory (cachedEvents.json)
• Filters: Only caches events where endDate > Date()
• Network monitoring: Observes NetworkMonitor.isConnected via Combine

Data Flow#

Gym Occupancy:

1. ContentView.onAppear → fetchGymOccupancyData()
2. GymService.fetchAllGymOccupancy() → GymOccupancyFetcher.fetchAll()
3. Concurrent POST requests for three facilities (McComas, War Memorial, Bouldering Wall)
4. HTML response parsed via regex for data-occupancy/data-remaining
5. Results stored in GymService @Published properties
6. UI updates via SwiftUI @ObservedObject binding

Events:

1. ContentView.onAppear → eventsViewModel.fetchEvents()
2. RSS feed fetched via URLSession.dataTask
3. XML parsed via RSSParser (NSXMLParser delegate)
4. Events filtered by endDate > Date()
5. Cached to JSON file, loaded on init if available

Widgets:

1. UnifiedGymTrackerProvider.getTimeline() called by WidgetKit
2. GymOccupancyFetcher.fetchForWidget() fetches occupancy (no remaining capacity)
3. Results stored in App Group UserDefaults (group.VTGymApp.D8VXFBV8SJ)
4. Fallback to cached values if fetch fails
5. Timeline policy: .after(15 minutes)

Facility IDs & Capacities#

mcComasFacilityId: "da73849e-434d-415f-975a-4f9e799b9c39"
warMemorialFacilityId: "55069633-b56e-43b7-a68a-64d79364988d"
boulderingWallFacilityId: "da838218-ae53-4c6f-b744-2213299033fc"

mcComasMaxCapacity: 600
warMemorialMaxCapacity: 1200
boulderingWallMaxCapacity: 8

Barcode System#

Storage:

• @AppStorage("gymBarcode") stores Codabar string (e.g., "A12345B")
• Optional @AppStorage("faceIDEnabled") for biometric protection

Scanning:

• BarcodeScannerView uses CodeScannerView (third-party library)
• Scans Codabar format (codeTypes: [.codabar])
• Validation: Ensures start/end characters are A/B/C/D
• Auto-prefix/suffix if missing: defaults to "A" prefix, "B" suffix

Generation:

• BarcodeGenerator uses CDCodabarView (third-party library)
• Generates UIImage from Codabar string
• Displayed in BarcodeDisplayOverlayView with brightness boost via BrightnessManager

Authentication:

• LocalAuthentication framework for Face ID/Touch ID
• LAContext.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics)
• Triggered before displaying stored barcode if faceIDEnabled == true

App Group & Shared Storage#

• App Group ID: group.VTGymApp.D8VXFBV8SJ
• Shared UserDefaults keys:
  • mcComasOccupancy (Int)
  • warMemorialOccupancy (Int)
  • boulderingWallOccupancy (Int)
  • lastFetchDate (Date)
• Used by: Main app, Widget extension, Watch app

UI Components#

ContentView:

• NavigationStack with grouped List
• Sections: War Memorial, McComas, Bouldering Wall, Events
• OccupancyCard displays occupancy with segmented progress bar
• Color thresholds: Green (0-50%), Orange (50-75%), Maroon (75-100%)

OccupancyCard:

• Segmented progress visualization
• Displays occupancy count and remaining capacity
• Network status indicator

EventCard:

• Displays event title, location, time, hosting organization
• Date range: Today through 14 days ahead

Widget System#

UnifiedGymTrackerProvider:

• Single timeline provider for all widget sizes
• getTimeline() fetches occupancy data
• Stores in App Group UserDefaults
• Timeline refresh: 15-minute intervals
• Widget types: Home screen widgets, Lock screen widgets

Watch App#

• WatchFacilitiesView displays gym occupancy
• WatchGymCardView shows individual facility status
• WatchSegmentedProgressBar visual indicator
• Shares data via App Group UserDefaults

Dependencies#

• CodeScanner: Barcode scanning (CodeScannerView)
• CDCodabarView: Codabar barcode generation
• SwiftUI: UI framework
• Combine: Reactive data flow
• WidgetKit: Widget system
• LocalAuthentication: Biometric authentication
• AVFoundation: Camera access for barcode scanning

Build Requirements#

• iOS 17.0+
• watchOS 10.0+
• Xcode 16.0+
• Swift 5.9+

Project Structure#

Gym Tracker (RC)/
├── Services/
│   ├── GymService.swift              # Main occupancy service
│   ├── GymOccupancyFetcher.swift     # HTTP fetching
│   ├── OccupancyHTMLParser.swift     # Regex HTML parsing
│   ├── Constants.swift                # Facility IDs, capacities, URLs
│   └── UnifiedGymTrackerProvider.swift # Widget timeline provider
├── Events/
│   ├── EventsViewModel.swift         # RSS fetching & caching
│   └── Event.swift                    # Event model
├── BarCode Scanner/
│   ├── BarcodeScannerView.swift      # Camera scanning UI
│   ├── BarcodeGenerator.swift        # Codabar image generation
│   ├── BarcodeDisplayView.swift      # Display overlay
│   ├── ManualIDInputView.swift       # Manual entry UI
│   └── BrightnessManager.swift       # Screen brightness control
├── ContentView.swift                 # Main app view
└── OccupancyCard.swift               # Occupancy display component

GymTrackerWidget/                      # Widget extension
GymTrackerWatch Watch App/             # Watch app
GymTrackerComplications/               # Watch complications

License#

This project is licensed under the MIT License. See the LICENSE file for full text.

Privacy Policy

Virginia Tech is not associated with this project