refactor(lms): encode bool by 0 and 1 in lms csv export/import

src/Model/Types/Lms.hs

@@ -39,6 +39,7 @@ derivePersistFieldJSON ''LmsStatus
 
 
 -- LMS Interface requires Bool to be encoded by 0 or 1 only
+{-
 data LmsBool = LmsUnset | LmsSet 
   deriving (Eq, Ord, Read, Show, Generic, Typeable, NFData)
   
@@ -61,3 +62,20 @@ instance Csv.FromField LmsBool where
     | i == "0"  = pure LmsUnset
     | i == "1"  = pure LmsSet
     | otherwise = empty
+-}     
+
+newtype LmsBool = LmsBool { lms2bool :: Bool }
+  deriving (Eq, Ord, Read, Show, Generic, Typeable)
+
+_lmsBool :: Iso' Bool LmsBool
+_lmsBool = iso LmsBool lms2bool
+
+instance Csv.ToField LmsBool where 
+  toField (LmsBool False) = "0"
+  toField (LmsBool True ) = "1"
+  
+instance Csv.FromField LmsBool where 
+  parseField i
+    | i == "0"  = pure $ LmsBool False
+    | i == "1"  = pure $ LmsBool True 
+    | otherwise = empty