onLive — SwiftUI lifecycle operators which fire exactly once.

Usable lifecycle guarantees for SwiftUI.

onAppear -> onLive
task -> whileLive

Usage

1. Add swiftui-on-live as a Swift Package Manager dependency.
2. import onLive within your view's file.
3. Replace your view's onAppear and task calls with onLive and whileLive.

Why?

SwiftUI's standard view lifecycle methods are sometimes called repeatedly — making binding a behavior to your view's lifecycle much more complicated.

.task {
    for await payload in createWebsocketConnection() {
        // This subscription can be created multiple times.
    }
}

This demo shows onAppear, task, and task's cancellation behavior called repeatedly (within a LazyVStack — the simplest reproduction case).

Notice that:

• onLive (replacing onAppear) and whileLive (replacing task) are called exactly once.
• whileLive's long running behaviors (like subscriptions in task) are cancelled once, after permanent view removal.

This demo can be run from the repo with swift run Example