yesod-dsl-0.1.1.5: codegen/get-by-id.cg

        ~{vn} <- do
            r <- get $ ((~{inputFieldRef ctx fr}) :: ~{en}Id)
            case r of
                Just e -> return e
                _ -> sendResponseStatus status400 $ A.object [  
                    "message" .= ("Could not get entity ~{en}" :: Text) 
                   ]