Unable to use then on ios swift promisekit - ios

Question

I created a promise which gets some data from API and returns it. Now what i am stuck is after getting the json data i need to store them on device storage (realm). After calling the promise when i try with then i get some error stating Cannot convert value of type '(Any) -> Void' to expected argument type '(_) -> _' . But when i try with done it works perfectly. But i need to use then to save the data on realm.
Following approch works fine
Translator().translators().done { data -> Void in
print(data[0].name)
}.catch { error in
print(error)
}
But following two approach fails
Translator().translators().then() { data -> Void in
print(data)
}.catch() {
(e: Error) in
print(e)
}
Above gives an error that says
Cannot convert value of type '(Any) -> Void' to expected argument type '(_) -> _'
and following approach gives another similar error
Translator().translators().then() {
(data: [Translator]) -> Void in
print(data[0].name)
}.catch() {
(e: Error) in
print(e)
}
error message:
Cannot convert value of type '([Translator]) -> Void' to expected argument type '([Translator]) -> _'
Promise i created:
func translators() -> Promise<[Translator]> {
return firstly {
Alamofire.request("http://192.168.0.107:3000/translatdors", method: .get).responseData()
}.map {
try JSONDecoder().decode([Translator].self, from: $0.data)
}
}
Image of my code and error

Answer 1

You have to return a promise when you do .then because until .done you are not finished. I don't see any issue in saving realm data in .done as your method has no return type.
Incase you still want to use .then, it can be done this way.
Translator().translators().then({ data -> Promise<[Translator]> in
return Promise.value(data)
}).done({ data in
// Save to realm
}).catch({ error in
print(error.localizedDescription)
})