Allow to remove only unused categories

1 files changed, 7 insertions, 2 deletions

diff --git a/common/src/Common/Validation/Atomic.hs b/common/src/Common/Validation/Atomic.hs
index 2a356df..4bb7cad 100644
--- a/common/src/Common/Validation/Atomic.hs
+++ b/common/src/Common/Validation/Atomic.hs
@@ -7,6 +7,7 @@ module Common.Validation.Atomic
   , color
   ) where
 
+import qualified Data.Char          as Char
 import           Data.Text          (Text)
 import qualified Data.Text          as T
 import           Data.Time.Calendar (Day)
@@ -47,6 +48,10 @@ day str =
     Just d  -> V.Success d
     Nothing -> V.Failure $ Msg.get Msg.Form_InvalidDate
 
--- TODO: validate
 color :: Text -> Validation Text Text
-color str = V.Success str
+color str =
+  if T.take 1 str == "#" && T.all Char.isHexDigit (T.drop 1 str) then
+    V.Success str
+
+  else
+    V.Failure (Msg.get Msg.Form_InvalidColor)