[SOLVED] Pass value over Promise in Swift

Pass value over Promise in Swift

I have a Promise chain like this

firstly {
   Network.shared.getInfo()
}
.then { info in
   Network.shared.getUserDetail(info)
}
.then { detail in
   Network.shared.getAddOn(detail)
}
.done { addOn in
 //do stuff with addOn
}
.catch { error in 
}

and I need to have all values (info, detail and addOn) in the .done Promise block. Is there a way to extend visibility or pass values throught Promise ?

I can't use when(fulfilled: []) because each value depends from the previous one.

Thanks.

Solution

You could propagate the inputs from your previous promise to the next promises by wrapping the new value and the previous one(s) in a tuple.

firstly {
   Network.shared.getInfo()
}
.then { info in
   (info, Network.shared.getUserDetail(info))
}
.then { info, detail in
   (info, detail, Network.shared.getAddOn(detail))
}
.done { info, detail, addOn in
 //do stuff with addOn
}
.catch { error in 
}

Alternatively, you could change your methods to return tuples themselves or to return a type which wraps the input arg and the newly generated return value.

So for instance change Network.shared.getUserDetail(info) from returning just UserDetail to returning (UserInfo, UserDetail).