SwiftUI.md

SwiftUI

SwiftUI has a lot of built-in support for concurrency.

Non-MainActor Isolation

Wait! As of the SDKs in Xcode 16, Swift's View now is isolated to the MainActor!. However, just in case you want to have a look at what was required before, here are some ideas.

Solution #1: Just use MainActor

Just slap an @MainActor on there to make things much easier.

@MainActor
struct MyView: View {
    var body: some View {
        Text("Body")
    }
}

Solution #2: Override View

This is a little more radical of a solution, but can save lots of typing. Swift makes it possible to override entire types within a module. So, you'd have to do this in any module directly, but it certainly does reduce the amount of boilerplate. I'd be a little careful with this one, but it is also ok to add redundant global actor annotations, so at least it is trivial to remove.

// do this once
@MainActor
protocol View: SwiftUI.View {
    @ViewBuilder
    var body: Self.Body { get }
}

// inherit MainActor isolation within the same module
struct MyView: View {
    var body: some View {
        Text("Body")
    }
}

EnvironmentKey/PreferencesKey

These can be hard to use! Check out the protocol section for ideas.