Send Alerts-Header when using async-massinput

src/Foundation.hs

@@ -1103,8 +1103,13 @@ instance Yesod UniWorX where
         headerMessagesMiddleware handler = (handler `finally`) . runMaybeT $ do
           isModal <- hasCustomHeader HeaderIsModal
           dbTableShortcircuit <- hasCustomHeader HeaderDBTableShortcircuit
-          $logDebugS "headerMessagesMiddleware" $ tshow (isModal, dbTableShortcircuit)
-          guard $ isModal || dbTableShortcircuit
+          massInputShortcircuit <- hasCustomHeader HeaderMassInputShortcircuit
+          $logDebugS "headerMessagesMiddleware" $ tshow (isModal, dbTableShortcircuit, massInputShortcircuit)
+          guard $ or
+            [ isModal
+            , dbTableShortcircuit
+            , massInputShortcircuit
+            ]
 
           lift . bracketOnError getMessages (mapM_ $ uncurry Yesod.addMessage) $ \msgs -> do
             Just msgs' <- return . forM msgs $ \(msgState, content) -> Message <$> fromPathPiece msgState <*> return content

src/Handler/Utils/Form/MassInput.hs

@@ -21,7 +21,7 @@ import Handler.Utils.Form (secretJsonField)
 import Handler.Utils.Form.MassInput.Liveliness
 import Handler.Utils.Form.MassInput.TH
 
-import Data.Aeson
+import Data.Aeson hiding (Result(..))
 
 import Algebra.Lattice hiding (join)
 
@@ -423,6 +423,10 @@ massInput MassInput{ miIdent = toPathPiece -> miIdent, ..} FieldSettings{..} fvR
     PageContent{..} <- widgetToPageContent $(widgetFile "widgets/massinput/massinput-standalone")
     ur <- getUrlRenderParams
 
+    case result of
+      FormFailure errs -> forM_ errs $ addMessage Error . toHtml -- Error messages get collected by middleware and added as header to response
+      _other           -> return () -- Completely ignore non-error results; we'll short circuit below
+
     sendResponse $ $(hamletFile "templates/widgets/massinput/massinput-standalone-wrapper.hamlet") ur
 
   let