Impressia/Vernissage/ViewModifiers/FirstAppear.swift

//
//  https://mczachurski.dev
//  Copyright © 2023 Marcin Czachurski and the repository contributors.
//  Licensed under the Apache License 2.0.
//

import Foundation
import SwiftUI

public extension View {
    func onFirstAppear(_ action: @escaping () async -> Void) -> some View {
        modifier(FirstAppear(action: action))
    }
}

private struct FirstAppear: ViewModifier {
    let action: () async -> Void
    @State private var hasAppeared = false

    func body(content: Content) -> some View {
        content.task {
            guard !hasAppeared else { return }
            hasAppeared = true

            await action()
        }
    }
}