Scotty: `reqHeader` not in scope

awasthishubh · March 3, 2020, 3:18pm

I am using Scotty to create a webserver and I need to get Authorisation header.
Tutorials say to use reqHeader but I am getting an error saying it’s not defined.
I have opened an issue as well but no one is there to help.

github.com/scotty-web/scotty

`reqHeader` not in scope

opened 07:43AM - 25 Feb 20 UTC

closed 08:44PM - 23 Mar 20 UTC

awasthishubh

So I started with Haskell recently and now I am learning Scotty to make simple w…eb server. I got this error which says `reqHeader` not in scope. I saw this code at different tutorials. Is something changed? Do I need to add any extra import? Code ``` haskell {-# LANGUAGE OverloadedStrings #-} import Web.Scotty import qualified Data.Text as T import Control.Monad.IO.Class import Network.HTTP.Types main = scotty 3000 $ do get "/" $ do liftIO $ putStrLn $ "XXXXXXXXXXXXXXXXXXXXXX" agent <- reqHeader "User-Agent" text agent ``` Error log: ```console Resolving dependencies... Configuring google-oauth-0.1.0.0... Building google-oauth-0.1.0.0... Failed to install google-oauth-0.1.0.0 Build log ( /home/shubh/.cabal/logs/google-oauth-0.1.0.0.log ): cabal: Entering directory '.' Configuring google-oauth-0.1.0.0... Building google-oauth-0.1.0.0... Preprocessing executable 'google-oauth' for google-oauth-0.1.0.0... [1 of 1] Compiling Main ( src/Main.hs, dist/build/google-oauth/google-oauth-tmp/Main.o ) src/Main.hs:10:18: error: • Variable not in scope: reqHeader :: [Char] -> Web.Scotty.Internal.Types.ActionT Data.Text.Internal.Lazy.Text IO Data.Text.Internal.Lazy.Text • Perhaps you meant ‘setHeader’ (imported from Web.Scotty) cabal: Leaving directory '.' cabal: Error: some packages failed to install: google-oauth-0.1.0.0 failed during the building phase. The exception was ```

Can anyone help me with this?

gilmi · March 4, 2020, 5:56am

I went looking for something similar to what you are looking for on the scotty docs on hackage and found the function header.

chris-martin · March 21, 2020, 7:18pm

Since you’re looking at a tutorial last updated in 2014, it’s a good idea to browse the change logs for the relevant library. Not everybody keeps a good change log, but most bigger packages do. On the main page for the scotty package on Hackage, there’s a “changelog” link near the top in the right column. So there you can see that reqHeader was renamed to header and deprecated in version 0.7.0, and then removed in version 0.8.0.