Building a Brewery Keg Tracker iOS App - Part 1

In this tutorial series, we'll build a brewery keg tracking app from scratch while learning Swift and iOS development. By the end, you'll have an app that can scan QR codes, track kegs, and eventually use LiDAR for 3D mapping.

What We're Building in Part 1

A simple two-tab iOS app:

Scanner Tab: QR code scanner to add kegs
Inventory Tab: List view of all scanned kegs

Prerequisites

Mac with Xcode installed
iPhone (for testing camera features)
Basic programming knowledge (any language)

Step 1: Create New Xcode Project

Open Xcode
Create new project → iOS → App
Product Name: KegTracker
organization Identifier: yourname
Interface: SwiftUI
Language: Swift

Step 2: Project Structure

We'll create these files:

KegTracker/
├── ContentView.swift (main tab view)
├── ScannerView.swift (QR scanner)
├── InventoryView.swift (keg list)
├── KegModel.swift (data model)
└── Info.plist (camera permissions)

Step 3: Data Model

First, let's define what a keg looks like in our app:

// KegModel.swift
import Foundation

struct Keg: Identifiable, Codable {
    let id = UUID()
    let qrCode: String
    let beerName: String
    let beerType: String
    let scanDate: Date
    var location: String = "Unassigned"

    var formattedDate: String {
        let formatter = DateFormatter()
        formatter.dateStyle = .medium
        return formatter.string(from: scanDate)
    }
}

class KegStore: ObservableObject {
    @Published var kegs: [Keg] = []

    func addKeg(qrCode: String, beerName: String, beerType: String) {
        let newKeg = Keg(
            qrCode: qrCode,
            beerName: beerName,
            beerType: beerType,
            scanDate: Date()
        )
        kegs.append(newKeg)
    }
}

Step 4: Main Tab View

Replace ContentView.swift with our tab structure:

// ContentView.swift
import SwiftUI

struct ContentView: View {
    @StateObject private var kegStore = KegStore()

    var body: some View {
        TabView {
            ScannerView()
                .tabItem {
                    Image(systemName: "qrcode.viewfinder")
                    Text("Scanner")
                }
                .environmentObject(kegStore)

            InventoryView()
                .tabItem {
                    Image(systemName: "list.bullet")
                    Text("Inventory")
                }
                .environmentObject(kegStore)
        }
    }
}

Step 5: QR Scanner View

Create the scanner interface:

// ScannerView.swift
import SwiftUI
import AVFoundation

struct ScannerView: View {
    @EnvironmentObject var kegStore: KegStore
    @State private var showingAddKeg = false
    @State private var scannedCode = ""

    var body: some View {
        NavigationView {
            VStack {
                Text("Point camera at QR code")
                    .font(.title2)
                    .padding()

                // QR Scanner will go here
                Rectangle()
                    .fill(Color.gray.opacity(0.3))
                    .frame(width: 300, height: 300)
                    .overlay(
                        Text("Camera View\n(Coming next)")
                            .multilineTextAlignment(.center)
                    )

                Button("Simulate Scan") {
                    scannedCode = "QR-\(Int.random(in: 1000...9999))"
                    showingAddKeg = true
                }
                .buttonStyle(.borderedProminent)
                .padding()

                Spacer()
            }
            .navigationTitle("Scanner")
            .sheet(isPresented: $showingAddKeg) {
                AddKegView(qrCode: scannedCode)
                    .environmentObject(kegStore)
            }
        }
    }
}

struct AddKegView: View {
    @EnvironmentObject var kegStore: KegStore
    @Environment(\.dismiss) private var dismiss

    let qrCode: String
    @State private var beerName = ""
    @State private var beerType = ""

    let beerTypes = ["IPA", "Lager", "Stout", "Pilsner", "Wheat", "Sour", "Porter"]

    var body: some View {
        NavigationView {
            Form {
                Section("QR Code") {
                    Text(qrCode)
                        .foregroundColor(.secondary)
                }

                Section("Beer Details") {
                    TextField("Beer Name", text: $beerName)

                    Picker("Beer Type", selection: $beerType) {
                        ForEach(beerTypes, id: \.self) { type in
                            Text(type).tag(type)
                        }
                    }
                }
            }
            .navigationTitle("Add Keg")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") { dismiss() }
                }

                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        kegStore.addKeg(
                            qrCode: qrCode,
                            beerName: beerName,
                            beerType: beerType.isEmpty ? "Unknown" : beerType
                        )
                        dismiss()
                    }
                    .disabled(beerName.isEmpty)
                }
            }
        }
    }
}

Step 6: Inventory View

Create the list to display kegs:

// InventoryView.swift
import SwiftUI

struct InventoryView: View {
    @EnvironmentObject var kegStore: KegStore

    var body: some View {
        NavigationView {
            List {
                ForEach(kegStore.kegs) { keg in
                    KegRowView(keg: keg)
                }
            }
            .navigationTitle("Inventory")
            .overlay {
                if kegStore.kegs.isEmpty {
                    ContentUnavailableView(
                        "No Kegs",
                        systemImage: "qrcode",
                        description: Text("Scan QR codes to add kegs to your inventory")
                    )
                }
            }
        }
    }
}

struct KegRowView: View {
    let keg: Keg

    var body: some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                Text(keg.beerName)
                    .font(.headline)
                Spacer()
                Text(keg.beerType)
                    .font(.caption)
                    .padding(.horizontal, 8)
                    .padding(.vertical, 2)
                    .background(Color.blue.opacity(0.2))
                    .cornerRadius(4)
            }

            Text("QR: \(keg.qrCode)")
                .font(.caption)
                .foregroundColor(.secondary)

            Text("Scanned: \(keg.formattedDate)")
                .font(.caption)
                .foregroundColor(.secondary)
        }
        .padding(.vertical, 2)
    }
}

Step 7: Camera Permissions

Add camera permission to Info.plist:

Open Info.plist
Add new entry: Privacy - Camera Usage Description
Value: "This app needs camera access to scan QR codes on kegs"

Testing Your App

Build and run on device (camera won't work in simulator)
Use "Simulate Scan" button to test the flow
Add a few test kegs and see them in inventory

What's Next

In Part 2, we'll add:

Real QR code scanning with camera
Search and filter functionality
Basic location assignment

Key Learning Points

SwiftUI basics: Views, state management, navigation
Data modeling: Structs, ObservableObject
Tab navigation: TabView and environmentObject
Forms and sheets: User input and modal presentation

Ready for Part 2? We'll make that QR scanner actually work with the camera!

Building a Brewery Keg Tracker iOS App - Part 1: QR Scanner & Basic Inventory