Improvements for 'update' form about elm-form HOT 8 CLOSED

-- VALIDATOR
valFloat : String -> Validation e (String, Float)
valFloat fieldName =
    Validate.map
        (\v -> (fieldName, v))
        (fieldName := float `andThen` minFloat 0)

valString : String -> Validation e (String, String)
valString fieldName =
    Validate.map
        (\v -> (fieldName, v))
        (fieldName := string `andThen` nonEmpty)

valMulti : (String -> Validation e a) -> List String -> Validation e (List a)
valMulti valFunc lst =
    case lst of
        [] -> succeed []
        (x::xs) ->
            succeed (::)
                `apply` (valFunc x)
                `apply` (valMulti valFunc xs)

valMulti' : (String -> Validation e a) -> List String -> Validation e (List a)
valMulti' valFunc =
  foldl (\f p -> succeed (::) `apply` (valFunc f) `apply` p) (succeed [])

defaultArea : Area
defaultArea =
   { areaDeleted       = False
   , areaName          = "New area"
   , areaMobileVisible = True
   , areaMobileActive  = True
   , areaMobileIndex   = 0
   , areaMobileDefault = False
   , areaImage         = Nothing
   , areaDescription   = Nothing
   }


initialAreaFields : Maybe Area -> Area -> List (String, Field.Field)
initialAreaFields maybeObject defaultObject =
  let
    o = Maybe.withDefault defaultObject maybeObject
  in
    [ "areaDeleted"       => Field.check o.areaDeleted
    , "areaName"          => Field.text o.areaName
    , "areaMobileVisible" => Field.check o.areaMobileVisible
    , "areaMobileActive"  => Field.check o.areaMobileActive
    , "areaMobileIndex"   => Field.text (o.areaMobileIndex |> toString)
    , "areaMobileDefault" => Field.check o.areaMobileDefault
    , "areaImage"         => Field.text (o.areaImage ? "")
    , "areaDescription"   => Field.text (o.areaDescription ? "")
    ]