Add a wrapper for traversing newtypes in formdata (#183)

Author: Madeline Trotter

docs/Examples/Form.example.purs

@@ -10,6 +10,7 @@ import Data.Array.NonEmpty (NonEmptyArray)
 import Data.Foldable (foldMap)
 import Data.Int as Int
 import Data.Lens (iso)
+import Data.Lens.Iso (mapping)
 import Data.Lens.Record (prop)
 import Data.Maybe (Maybe(..), isNothing, maybe)
 import Data.Monoid as Monoid
@@ -30,6 +31,7 @@ import Lumi.Components.Form (FormBuilder, Validated)
 import Lumi.Components.Form as F
 import Lumi.Components.Form.Defaults (formDefaults)
 import Lumi.Components.Form.Table as FT
+import Lumi.Components.Form.Validation (ValidatedNewtype, _ValidatedNewtype)
 import Lumi.Components.Input as Input
 import Lumi.Components.LabeledField (RequiredField(..))
 import Lumi.Components.Modal (dialog)
@@ -199,7 +201,9 @@ type User =
   , descriptiveCheckbox :: Boolean
   , height :: Validated String
   , addresses :: Validated (Array Address)
-  , pets :: Validated (Array Pet)
+  , pets :: Validated (Array (ValidatedNewtype Pet))
+  -- ^ validation helpers like `setModified` need a little assistance getting
+  --     into Newtypes like `Pet`, hence this `ValidatedNewtype` wrapper
   , leastFavoriteColors :: Validated (Array String)
   , notes :: String
   , avatar :: Maybe Upload.FileId
@@ -220,14 +224,16 @@ type ValidatedUser =
   , avatar :: Maybe Upload.FileId
   }
 
-type Pet =
+newtype Pet = Pet
   { firstName :: Validated String
   , lastName :: Validated String
   , animal :: Validated (Maybe String)
   , age :: Validated String
   , color :: Validated (Maybe String)
   }
 
+derive instance ntPet :: Newtype Pet _
+
 type ValidatedPet =
   { name :: NonEmptyString
   , animal :: String
@@ -337,7 +343,7 @@ userForm = ado
 
   F.section "Pets"
   pets <-
-    F.focus (prop (SProxy :: SProxy "pets"))
+    F.focus (prop (SProxy :: SProxy "pets") <<< mapping (mapping _ValidatedNewtype))
     $ F.warn (\pets ->
         Monoid.guard (Array.null pets) (pure "You should adopt a pet.")
       )

src/Lumi/Components/Form/Validation.purs

@@ -10,6 +10,7 @@ module Lumi.Components.Form.Validation
   , _Validated, _Fresh, _Modified
   , setFresh, setModified
   , ModifyValidated(..)
+  , ValidatedNewtype(..), _ValidatedNewtype
   , class CanValidate, fresh, modified, fromValidated
   , validated
   , warn
@@ -26,10 +27,11 @@ import Data.Enum (toEnum)
 import Data.Eq (class Eq1)
 import Data.Foldable (foldMap)
 import Data.Int as Int
-import Data.Lens (Lens, Prism', lens, over, prism', review, view)
+import Data.Lens (Lens, Prism', Iso', lens, over, prism', review, view)
+import Data.Lens.Iso.Newtype (_Newtype)
 import Data.Maybe (Maybe(..))
 import Data.Monoid (guard)
-import Data.Newtype (un)
+import Data.Newtype (class Newtype, un)
 import Data.Nullable (notNull)
 import Data.Number as Number
 import Data.Ord (class Ord1)
@@ -201,6 +203,13 @@ setModified = mapping (ModifyValidated (Modified <<< view _Validated))
 -- | records containing `Validated` values.
 newtype ModifyValidated = ModifyValidated (Validated ~> Validated)
 
+newtype ValidatedNewtype a = ValidatedNewtype a
+
+derive instance ntMVP :: Newtype (ValidatedNewtype a) _
+
+_ValidatedNewtype :: forall s a. Newtype s a => Iso' (ValidatedNewtype s) a
+_ValidatedNewtype = _Newtype <<< _Newtype
+
 instance modifyValidated :: Mapping ModifyValidated a a => Mapping ModifyValidated (Validated a) (Validated a) where
   mapping m@(ModifyValidated f) = over _Validated (mapping m) <<< f
 else instance modifyValidatedRecord ::
@@ -210,6 +219,8 @@ else instance modifyValidatedRecord ::
   mapping d = hmap d
 else instance modifyValidatedArray :: Mapping ModifyValidated a a => Mapping ModifyValidated (Array a) (Array a) where
   mapping d = map (mapping d)
+else instance modifyValidatedNewtype :: (Newtype a b, Mapping ModifyValidated b b) => Mapping ModifyValidated (ValidatedNewtype a) (ValidatedNewtype a) where
+  mapping d = over (_Newtype <<< _Newtype) (mapping d)
 else instance modifyValidatedIdentity :: Mapping ModifyValidated a a where
   mapping _ = identity