servant/servant-jquery/test/Servant/JQuerySpec/CustomHeaders.hs

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{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
module Servant.JQuerySpec.CustomHeaders where
import Control.Lens
import Data.Monoid
import Data.Proxy
import GHC.TypeLits
import Servant.API
import Servant.JQuery
-- | This is a hypothetical combinator that fetches an Authorization header.
-- The symbol in the header denotes what kind of authentication we are
-- using -- Basic, Digest, whatever.
data Authorization (sym :: Symbol) a
instance (KnownSymbol sym, HasJQ sublayout)
=> HasJQ (Authorization sym a :> sublayout) where
type JQ' (Authorization sym a :> sublayout) = JQ' sublayout
jqueryFor Proxy req = jqueryFor (Proxy :: Proxy sublayout) $
req & reqHeaders <>~ [ ReplaceHeaderArg "Authorization" $
tokenType (symbolVal (Proxy :: Proxy sym)) ]
where
tokenType t = t <> " {Authorization}"
-- | This is a combinator that fetches an X-MyLovelyHorse header.
data MyLovelyHorse a
instance (HasJQ sublayout)
=> HasJQ (MyLovelyHorse a :> sublayout) where
type JQ' (MyLovelyHorse a :> sublayout) = JQ' sublayout
jqueryFor Proxy req = jqueryFor (Proxy :: Proxy sublayout) $
req & reqHeaders <>~ [ ReplaceHeaderArg "X-MyLovelyHorse" tpl ]
where
tpl = "I am good friends with {X-MyLovelyHorse}"
-- | This is a combinator that fetches an X-WhatsForDinner header.
data WhatsForDinner a
instance (HasJQ sublayout)
=> HasJQ (WhatsForDinner a :> sublayout) where
type JQ' (WhatsForDinner a :> sublayout) = JQ' sublayout
jqueryFor Proxy req = jqueryFor (Proxy :: Proxy sublayout) $
req & reqHeaders <>~ [ ReplaceHeaderArg "X-WhatsForDinner" tpl ]
where
tpl = "I would like {X-WhatsForDinner} with a cherry on top."