optionalFieldOrNullWithOmittedDefault

autodocodec/src/Autodocodec/Aeson/Decode.hs

@@ -9,7 +9,6 @@ module Autodocodec.Aeson.Decode where
 import Autodocodec.Class
 import Autodocodec.Codec
 import Autodocodec.DerivingVia
-import Control.Applicative
 import Control.Monad
 import Data.Aeson as JSON
 import Data.Aeson.Types as JSON

autodocodec/src/Autodocodec/Class.hs

@@ -270,3 +270,23 @@ optionalFieldWithOmittedDefault' ::
   output ->
   ObjectCodec output output
 optionalFieldWithOmittedDefault' key defaultValue = optionalFieldWithOmittedDefaultWith' key codec defaultValue
+
+optionalFieldOrNullWithOmittedDefault ::
+  (Eq output, HasCodec output) =>
+  -- | Key
+  Text ->
+  -- | Default value
+  output ->
+  -- | Documentation
+  Text ->
+  ObjectCodec output output
+optionalFieldOrNullWithOmittedDefault key defaultValue doc = optionalFieldOrNullWithOmittedDefaultWith key codec defaultValue doc
+
+optionalFieldOrNullWithOmittedDefault' ::
+  (Eq output, HasCodec output) =>
+  -- | Key
+  Text ->
+  -- | Default value
+  output ->
+  ObjectCodec output output
+optionalFieldOrNullWithOmittedDefault' key defaultValue = optionalFieldOrNullWithOmittedDefaultWith' key codec defaultValue

autodocodec/src/Autodocodec/Codec.hs

@@ -569,6 +569,40 @@ optionalFieldWithOmittedDefaultWith' ::
   ObjectCodec output output
 optionalFieldWithOmittedDefaultWith' key c defaultValue = OptionalKeyWithOmittedDefaultCodec key c defaultValue Nothing
 
+optionalFieldOrNullWithOmittedDefaultWith ::
+  Eq output =>
+  -- | Key
+  Text ->
+  -- | Codec for the value
+  JSONCodec output ->
+  -- | Default value
+  output ->
+  -- | Documentation
+  Text ->
+  ObjectCodec output output
+optionalFieldOrNullWithOmittedDefaultWith key c defaultValue doc = dimapCodec f g $ optionalFieldWithOmittedDefaultWith key (maybeCodec c) (Just defaultValue) doc
+  where
+    f = \case
+      Just v -> v
+      Nothing -> defaultValue
+    g v = if v == defaultValue then Nothing else Just v
+
+optionalFieldOrNullWithOmittedDefaultWith' ::
+  Eq output =>
+  -- | Key
+  Text ->
+  -- | Codec for the value
+  JSONCodec output ->
+  -- | Default value
+  output ->
+  ObjectCodec output output
+optionalFieldOrNullWithOmittedDefaultWith' key c defaultValue = dimapCodec f g $ optionalFieldWithOmittedDefaultWith' key (maybeCodec c) (Just defaultValue)
+  where
+    f = \case
+      Just v -> v
+      Nothing -> defaultValue
+    g v = if v == defaultValue then Nothing else Just v
+
 -- | An optional, or null, field
 --
 -- During decoding, the field may be in the object. 'Nothing' will be parsed if it is not.