Elm’s Task library gives you lots of options to combine Tasks of different types, execute them in a specific order, and change their result and error types. Mastering this library makes Tasks a pleasure to use.
Examples
update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
case msg of
DealHand ->
let
localTask =
locallyStore updated
|> Task.mapError LocallyStoreError
remoteTask value =
remotelyStore value model
|> Task.mapError (RemotelyStoreError << httpErrorToString)
cmd =
localTask `andThen` remoteTask
|> Task.perform StorageFail StorageSucceed
in
model ! [cmd]
StorageFail error ->
let
updated = updateModelFromErrorType error model
in
updated ! []
StorageSucceed value->
model ! []