SwiftJotai

SwiftJotai is an atomic approach to global SwiftUI state management, inspired by Jotai.

Getting Started

To use SwiftJotai in your project, add this repository to the Package.swift manifest:

// swift-tools-version:5.7
import PackageDescription

let package = Package(
  name: "MyPackage",
  dependencies: [
    .package(url: "https://github.com/unixzii/SwiftJotai.git", .branch("main")),
  ],
  targets: [
    .target(name: "MyApp", dependencies: [
      .product(name: "SwiftJotai", package: "SwiftJotai"),
    ]),
  ]
)

Tutorial

Atom

The Atom is a config for an atomic state, as it's just a definition and it doesn't yet hold a value.

An atom config is an immutable object. The atom config object doesn't hold a value. The atom value exists in a store.

let priceAtom = Atom(10)
let messageAtom = Atom("hello")

You can create derived atoms, we pass a getter closure when doing so:

let doubledPriceAtom = Atom { store in
    return store.get(priceAtom) * 2
}

Store

The Store is an object where state values live in. You can create you own stores or just use the shared instance via Store.shared.

You can call...

• get: to get the value of an atom.
• set: to update the value of an atom.
• subscribe: to subscribe the updates of an atom.

Cancel a subscription

Store.subscribe returns a Disposable object. You must call the dispose method when the subscription is no longer needed, or there may be memory leaks.

AtomValue

To combine SwiftJotai with SwiftUI, AtomValue is your friend. It's an ObservableObject which can be used in any SwiftUI views to trigger re-renders when the atom updates.

let countAtom = Atom(0)

struct CounterView: View {
    @StateObject var count = AtomValue(countAtom)

    var body: some View {
        Text("\(count.value)")
    }
}

License

MIT