How to set a tuple in a AnyPublisher in SwiftUI

Question

good morning community,

I have a very good question that I try to implement in a project but I am something new to combine I want to do a function to check some permissions, but I want to return an AnyPublisher with a tuple inside, could someone help me who has already done it or know how to do it?

I put my code below.

func returnedPermisionReminderAuthorizationStatus(reminderPermission:EKAuthorizationStatus,calendarPermission:EKAuthorizationStatus) -> AnyPublisher<(EKAuthorizationStatus,EKAuthorizationStatus),Never>{

    var reminderPermissionToPass:EKAuthorizationStatus =  .notDetermined
    var calendarPermissionToPass:EKAuthorizationStatus =  .notDetermined
    
    switch (reminderPermission){
    case .notDetermined:
      return Just(reminderPermissionToPass).eraseToAnyPublisher()
    case .restricted:
        reminderPermissionToPass = .restricted
        return Just(reminderPermissionToPass).eraseToAnyPublisher()
    case .denied:
        reminderPermissionToPass = .denied
        return Just(reminderPermissionToPass).eraseToAnyPublisher()
    case .authorized:
        reminderPermissionToPass = .authorized
        return Just(reminderPermissionToPass).eraseToAnyPublisher()
    @unknown default:
        reminderPermissionToPass = .notDetermined
        return Just(reminderPermissionToPass).eraseToAnyPublisher()
    }

}

Is it possible to send a tuple in a just?

It is completely fine to pass a tuple with Just. But in your code, you're returning a single EKAuthorizationStatus value, not a tuple (the function expects to return a tuple). Change them to return a tuple such as `Just((.notDetermined, .notDetermined)).eraseToAnyPublisher` or whatever it is supposed to be for the case. — Cenk Bilgen, Aug 10 '21 at 17:33
Rather than sending a tuple take advantage of the `Error` type. For example you could send `true` on `authorized`, `false` on `notDetermined` and an error on the other cases. — vadian, Aug 10 '21 at 17:50
Agree with @vaidan, a status and Error is probably more useful. Even though you can send tuple of two status's and Never failure. — Cenk Bilgen, Aug 10 '21 at 18:36
For a better way to check for authorization at the head of a Combine pipeline see https://stackoverflow.com/a/60418000/341994 — matt, Aug 10 '21 at 22:01

score 2 · Answer 1 · answered Aug 10 '21 at 20:55

You can send a tuple from Just like this:

func returnedPermisionReminderAuthorizationStatus(
    reminderPermission: EKAuthorizationStatus,
    calendarPermission: EKAuthorizationStatus
) -> AnyPublisher<(EKAuthorizationStatus,EKAuthorizationStatus),Never>{
    Just((reminderPermission,calendarPermission))
        .eraseToAnyPublisher()
}

score 0 · Answer 2 · answered Aug 10 '21 at 17:31

0

What about a PassthroughSubject ? If yes then try the following code :

let someResponse = PassthroughSubject<(Bool,String), Never>()

and then to receive

    .onReceive(someResponse, perform: { (boolValue,StringValue) in

    })

answered Aug 10 '21 at 17:31

Osman

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How to set a tuple in a AnyPublisher in SwiftUI

2 Answers2