1 files changed, 36 insertions, 0 deletions
diff --git a/src/client/Model/Frequency.elm b/src/client/Model/Frequency.elm
new file mode 100644
index 0000000..40f9893
--- /dev/null
+++ b/src/client/Model/Frequency.elm
@@ -0,0 +1,36 @@
+module Model.Frequency exposing
+  ( Frequency(..)
+  , decoder
+  , validate
+  , fromString
+  )
+
+import Json.Decode as Decode exposing (Decoder)
+import Json.Decode.Extra as Decode
+
+import Form.Validate as Validate exposing (Validation)
+
+type Frequency = Punctual | Monthly
+
+decoder : Decoder Frequency
+decoder =
+  let frequencyResult input =
+        fromString input
+          |> Result.fromMaybe ("Could not deduce Punctual nor Monthly from " ++ input)
+  in  Decode.string |> Decode.andThen (Decode.fromResult << frequencyResult)
+
+validate : Validation String Frequency
+validate =
+  Validate.customValidation Validate.string (\str ->
+    fromString str
+      |> Result.fromMaybe (Validate.customError "InvalidFrequency")
+  )
+
+fromString : String -> Maybe Frequency
+fromString str =
+  if str == toString Punctual then
+    Just Punctual
+  else if str == toString Monthly then
+    Just Monthly
+  else
+    Nothing