How do I store a Swift enum in NSUserDefaults with TypedDefaults?

Define your enum to conform to DefaultsConvertible by implementing serialize() to return a raw value (e.g., Int) and init?(_ object:) to initialize from that raw value, as demonstrated in the CameraConfig example with the Size enum.

TypedDefaults vs Codable for UserDefaults in Swift – which is better?

TypedDefaults offers compile-time type safety and dependency injection for testability, but Codable provides automatic serialization with less code for many types. Choose based on whether you prioritize testing flexibility or reduced boilerplate.

Can I use TypedDefaults with SwiftUI?

Yes, TypedDefaults can be integrated into SwiftUI apps by using it in view models or environments to manage settings, but it doesn't provide direct property wrappers like @AppStorage, so some wiring is required.

How to handle data migration when changing custom types in TypedDefaults?

You need to implement custom logic in the init?(_ object:) method to handle legacy data formats, as the library doesn't offer built-in versioning or migration tools, which can be error-prone.

What are the performance implications of using TypedDefaults?

Performance is similar to native NSUserDefaults since it wraps standard calls, but serialization and deserialization of complex types might introduce overhead if not optimized, especially for large or nested structures.

Does TypedDefaults support storing arrays of custom types?

Yes, but you must ensure array elements conform to DefaultsConvertible and handle serialization in the parent type's methods, which can add complexity for nested data structures.

TypedDefaults — Type-Safe Swift NSUserDefaults Utility

What is TypedDefaults?

TypedDefaults is a Swift utility library that enables type-safe interaction with NSUserDefaults, Apple's key-value storage system for iOS and macOS apps. It allows developers to store custom Swift types (like structs and enums) directly in NSUserDefaults without manual serialization, reducing boilerplate and preventing runtime type errors. The library provides a protocol-driven approach to define how types are saved and retrieved, ensuring compile-time safety.

Target Audience

iOS and macOS developers working with Swift who need to persistently store app settings or configuration data in a type-safe manner. It's particularly useful for developers who want to avoid the pitfalls of stringly-typed keys and manual type casting when using NSUserDefaults.

Value Proposition

Developers choose TypedDefaults because it eliminates the risk of runtime crashes from incorrect type casting in NSUserDefaults, while also providing built-in support for dependency injection to make code more testable. Its lightweight, protocol-based design integrates seamlessly with Swift's type system without requiring heavy dependencies.

TypedDefaults is a utility library to type-safely use NSUserDefaults.

Use Cases

Best For

Storing app settings or user preferences with custom Swift types
Ensuring type safety when using NSUserDefaults in Swift projects
Unit testing code that depends on persistent storage by injecting in-memory stores
Reducing boilerplate code for serializing and deserializing custom types
Modernizing legacy Objective-C NSUserDefaults usage in Swift codebases
Building SwiftUI or UIKit apps that require type-safe configuration storage

Not Ideal For

Projects using Swift's Codable for automatic serialization of complex nested types
Applications requiring storage for large datasets or sensitive data beyond NSUserDefaults' capabilities
Teams preferring SwiftUI's @AppStorage for simple key-value pairs with zero boilerplate

Pros & Cons

Pros

Compile-Time Type Safety

Ensures custom types stored in NSUserDefaults are checked at compile time, eliminating runtime errors from incorrect casting, as enforced by the DefaultsConvertible protocol.

Enhanced Testability

Provides InMemoryStore and AnyStore for dependency injection, allowing unit testing by replacing persistent storage with in-memory mocks, as shown in the CameraViewController example.

Swift-Centric Design

Works with Swift structs, enums, and classes without requiring NSObject inheritance, promoting modern Swift patterns without Objective-C baggage.

Clear Protocol Contract

The DefaultsConvertible protocol defines a standard way for serialization and deserialization, ensuring consistency across custom types in the codebase.

Cons

Manual Serialization Overhead

Each custom type must implement serialize() and init?(_ object:) methods manually, adding boilerplate code compared to automatic solutions like Codable.

Tied to NSUserDefaults Limitations

Inherits constraints such as unsuitability for large data or complex queries, and lacks built-in encryption for sensitive information, limiting its use cases.

Potential Maintenance Burden

The library requires Swift 4.0 and Xcode 9, which may be outdated for newer projects, and users must handle updates or migration themselves without built-in tooling.

Frequently Asked Questions

What is TypedDefaults?

Target Audience

Value Proposition

Use Cases

Best For

Storing app settings or user preferences with custom Swift types
Ensuring type safety when using NSUserDefaults in Swift projects
Unit testing code that depends on persistent storage by injecting in-memory stores
Reducing boilerplate code for serializing and deserializing custom types
Modernizing legacy Objective-C NSUserDefaults usage in Swift codebases
Building SwiftUI or UIKit apps that require type-safe configuration storage

Not Ideal For

Projects using Swift's Codable for automatic serialization of complex nested types
Applications requiring storage for large datasets or sensitive data beyond NSUserDefaults' capabilities
Teams preferring SwiftUI's @AppStorage for simple key-value pairs with zero boilerplate

Pros & Cons

Pros

Compile-Time Type Safety

Ensures custom types stored in NSUserDefaults are checked at compile time, eliminating runtime errors from incorrect casting, as enforced by the DefaultsConvertible protocol.

Enhanced Testability

Provides InMemoryStore and AnyStore for dependency injection, allowing unit testing by replacing persistent storage with in-memory mocks, as shown in the CameraViewController example.

Swift-Centric Design

Works with Swift structs, enums, and classes without requiring NSObject inheritance, promoting modern Swift patterns without Objective-C baggage.

Clear Protocol Contract

The DefaultsConvertible protocol defines a standard way for serialization and deserialization, ensuring consistency across custom types in the codebase.

Cons

Manual Serialization Overhead

Each custom type must implement serialize() and init?(_ object:) methods manually, adding boilerplate code compared to automatic solutions like Codable.

Tied to NSUserDefaults Limitations

Inherits constraints such as unsuitability for large data or complex queries, and lacks built-in encryption for sensitive information, limiting its use cases.

Potential Maintenance Burden

The library requires Swift 4.0 and Xcode 9, which may be outdated for newer projects, and users must handle updates or migration themselves without built-in tooling.

Frequently Asked Questions

TypedDefaults

What is TypedDefaults?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

TypedDefaults

What is TypedDefaults?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?