Trait SwiftUiBuilder

Source

pub trait SwiftUiBuilder: Sized {
    // Required methods
    fn params<M>(self, params: impl IntoReactive<String, M>) -> Self;
    fn state_key(self, key: impl Into<String>) -> Self;
}

Expand description

Builder methods of SwiftUi, reachable through a Decorated (docs/api-style.md “Typed builders and erasure”): generic modifiers and typed ones chain in any order.

Required Methods§

Source

fn params<M>(self, params: impl IntoReactive<String, M>) -> Self

The JSON params string: a constant, a Signal<String>, or a Fn() -> String. When it’s reactive the hosted view follows it live: each change re-invokes the provider’s body with the new JSON (@State inside the view survives, see the crate docs).

Source

fn state_key(self, key: impl Into<String>) -> Self

Keep the hosted view’s SwiftUI state across unmount/remount. Without a key, leaving the piece’s branch (a tab switch, a when() going false, a page navigation) disposes the hosting view and its @State with it; with one, the native half retains the hosting view under key and hands the same instance back on the next mount, so sliders, scroll positions, @State/@StateObject all survive, and the mount’s current params are re-applied.

The key pins one hosting view for the app’s lifetime, so use it for the handful of views that want persistence, not per-row content. At most one live instance per key: two mounted pieces sharing a key would fight over one native view.