SwiftUI Alert with Publisher

SwiftUIAlertWithPublisher.swift

import SwiftUI
import Combine

struct AlertWithPublisher<P>: ViewModifier where P: Publisher, P.Failure == Never {
    let publisher: P
    let alertContent: (P.Output?) -> Alert

    @State private var isShowingAlert = false
    @State private var publisherOutput: P.Output? = nil

    func body(content: Content) -> some View {
        content
            .alert(isPresented: self.$isShowingAlert) {
                self.alertContent(self.publisherOutput)
            }
            .onReceive(publisher) { output in
                self.publisherOutput = output
                self.isShowingAlert.toggle()
            }
    }
}

extension View {
    func alert<P>(onReceive publisher: P, content: @escaping (P.Output?) -> Alert) -> some View where P: Publisher, P.Failure == Never {
        modifier(AlertWithPublisher(publisher: publisher, alertContent: content))
    }
}

/* Usage

.alert(onReceive: publisher) { output in
    Alert(title: Text("Alert"), message: Text("Presented from publisher."), dismissButton: .cancel())
}

*/