SwiftUI Error Handling: Graceful User Feedback with Result Types

Use @State with Result<Data, Error>? to handle async operations cleanly. This approach lets you track loading, success, and error states in a single property, making your UI logic more predictable.

This pattern creates reusable error views that provide consistent user experience across your app. The `ErrorView` component encapsulates error display logic and retry functionality, while the main view focuses on business logic using clean state management with `Result` types.

struct ErrorView: View {
    let error: Error
    let retry: () -> Void
    
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "exclamationmark.triangle")
                .font(.largeTitle)
                .foregroundColor(.orange)
            
            Text("Something went wrong")
                .font(.headline)
            
            Text(error.localizedDescription)
                .font(.body)
                .multilineTextAlignment(.center)
                .foregroundColor(.secondary)
            
            Button("Try Again", action: retry)
                .buttonStyle(.borderedProminent)
        }
        .padding()
    }
}

struct ContentView: View {
    @State private var result: Result<[String], Error>?
    
    var body: some View {
        NavigationView {
            Group {
                switch result {
                case .success(let items):
                    List(items, id: \.self) { item in
                        Text(item)
                    }
                case .failure(let error):
                    ErrorView(error: error) {
                        loadData()
                    }
                case nil:
                    ProgressView("Loading...")
                }
            }
            .navigationTitle("Items")
            .task { loadData() }
        }
    }
    
    private func loadData() {
        result = nil
        // Simulate async operation
        Task {
            await MainActor.run {
                result = .success(["Item 1", "Item 2", "Item 3"])
            }
        }
    }
}

Why This is a Best Practice

Centralizing error handling reduces code duplication, ensures consistent UX patterns, and makes debugging easier. The `Result` type provides type safety and clear state representation, while the reusable `ErrorView` promotes maintainability and allows for easy styling updates across the entire app.

struct ErrorView: View {
    let error: Error
    let retry: () -> Void
    
    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "exclamationmark.triangle")
                .font(.largeTitle)
                .foregroundColor(.orange)
            
            Text("Something went wrong")
                .font(.headline)
            
            Text(error.localizedDescription)
                .font(.body)
                .multilineTextAlignment(.center)
                .foregroundColor(.secondary)
            
            Button("Try Again", action: retry)
                .buttonStyle(.borderedProminent)
        }
        .padding()
    }
}

struct ContentView: View {
    @State private var result: Result<[String], Error>?
    
    var body: some View {
        NavigationView {
            Group {
                switch result {
                case .success(let items):
                    List(items, id: \.self) { item in
                        Text(item)
                    }
                case .failure(let error):
                    ErrorView(error: error) {
                        loadData()
                    }
                case nil:
                    ProgressView("Loading...")
                }
            }
            .navigationTitle("Items")
            .task { loadData() }
        }
    }
    
    private func loadData() {
        result = nil
        // Simulate async operation
        Task {
            await MainActor.run {
                result = .success(["Item 1", "Item 2", "Item 3"])
            }
        }
    }
}

Why This is a Best Practice

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SwiftUI Error Handling: Graceful User Feedback with Result Types

Why This is a Best Practice