# pfw-sharing

> Share and persist values across your application with the Sharing library

- Author: LoopingStudio
- Repository: LoopingStudio/ApertureTokenManager
- Version: 20260206182004
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-06
- Source: https://github.com/LoopingStudio/ApertureTokenManager
- Web: https://mule.run/skillshub/@@LoopingStudio/ApertureTokenManager~pfw-sharing:20260206182004

---

---
name: pfw-sharing
description: Share and persist values across your application with the Sharing library
license: Proprietary. LICENSE has complete terms
metadata:
  short-description: Share and persist values across your application
---

# Sharing

## Goal

Share and persist values across your application with the [Sharing] library.

[Sharing]: http://github.com/pointfreeco/swift-sharing

## Quick start

1. Add the `swift-sharing` package dependency from `2.0.0` or newer.
2. Add the `Sharing` product to your target's dependencies.
3. `import Sharing` as needed

## API interface

Full API interface for when solution can't be found elsewhere: `references/interface/Sharing.swiftinterface`

## How to persist a value to app storage (user defaults)

Use the `appStorage` strategy:

```swift
@Shared(.appStorage("isReduceMotionEnabled"))
var isReduceMotionEnabled = false
```

* **DO NOT** use invalid characters (`.`, `@`) in app storage keys

## How to persist a value to the file system

Use the `fileStorage` strategy with a codable value:

```swift
@Shared(.fileStorage(.applicationSupportDirectory.appending(component: "settings.json")))
var settings = Settings()
```

## How to add a type-safe default to a strategy

### Step 1: Extend `SharedKey` (or `SharedReaderKey`) with the default

```swift
extension SharedKey where Self == AppStorageKey<Bool>.Default {
  static var isReduceMotionEnabled: Self {
    Self[.appStorage("isReduceMotionEnabled"), default: false]
  }
}
```

### Step 2: Use leading dot-syntax as the strategy

```swift
@Shared(.isReduceMotionEnabled) var isReduceMotionEnabled
```

## How to share a value type as if it were a reference

Use `@Shared` without a strategy:

```swift
@Shared var currentUser: User
```

## How to bind a `@Shared` value to a SwiftUI view

Pass the projected `$shared` value to `Binding.init(_:)`:

```swift
@Shared var isReduceMotionEnabled: Bool

Toggle("Reduce motion", isOn: Binding($isReduceMotionEnabled))
```

## How to use `@Shared` in an observable model

Use `@ObservationIgnored` (`@Shared` manages its own observation):

```swift
@ObservationIgnored
@Shared(.appStorage("isReduceMotionEnabled"))
var isReduceMotionEnabled = false
```

## How to transform a shared parent to a shared child

```swift
@Shared var settings: Settings

$settings.isReduceMotionEnabled  // Shared<Bool>
```

## How to unwrap a shared optional value

```swift
@Shared var currentUser: User?

if let unwrappedSharedUser = Shared($currentUser) {
  ...
}
```

## How to observe changes to a shared value

Using the Observation framework:

```swift
@Shared var currentUser: User?

let isLoggedInAsyncSequence = Observations { currentUser != nil }
```

Using the Combine framework:

```swift
@Shared var currentUser: User?

let isLoggedInPublisher = $currentUser.publisher.map { $0 != nil }
```

* **DO** prefer Observation over Combine

## How to persist a value to a custom backend

TODO