Provides a task modifier with an optional binding that will run the task if the binding is set to a non-nil value and reset it to nil once the task is done. The purpose of this is to bind a one-shot task to the view, i.e. the cancellation is automatically performed if the view should be dismissed.

View+TaskID.swift

/// Provides a task modifier with an optional binding that will run the task if the binding is set to a
/// non-nil value and reset it to nil once the task is done.
///
/// The purpose of this is to bind a one-shot task to the view, i.e. the cancellation is automatically
/// performed if the view should be dismissed.
struct TaskViewModifier<T: Equatable>: ViewModifier {

    @Binding var taskId: T?
    let action: @Sendable (_: T) async -> Void

    func body(content: Content) -> some View {
        ZStack {
            content
                .task(id: taskId) {
                    guard let taskId = taskId else {
                        return
                    }
                    await action(taskId)

                    self.taskId = nil
                }
        }
    }
}

public extension View {
    /// Provides a task modifier with an optional binding that will run the task if the binding is set to a
    /// non-nil value and reset it to nil once the task is done.
    ///
    /// The purpose of this is to bind a one-shot task to the view, i.e. the cancellation is automatically
    /// performed if the view should be dismissed.
    ///
    /// - Parameters:
    ///   - taskId: A binding to an optional `T` that will trigger the task when set to a non-nil value.
    ///   - action: The async action to perform.
    func task<T: Equatable>(_ value: Binding<T?>, _ action: @escaping @Sendable (_: T) async -> Void) -> some View {
        modifier(TaskViewModifier<T>(taskId: value, action: action))
    }
}