Servant.API.Header

Documentation

type Header = Header' '[Optional, Strict]

Extract the given header's value as a value of type a. I.e. header sent by client, parsed by server.

Example:

>>> newtype Referer = Referer Text deriving (Eq, Show)
>>> 
>>> -- GET /view-my-referer
>>> type MyApi = "view-my-referer" :> Header "from" Referer :> Get '[JSON] Referer

data Header' (mods :: [*]) (sym :: Symbol) a

Instances

(KnownSymbol h, ToHttpApiData v) => AddHeader h v (Headers ((:) * fst rest) a) (Headers ((:) * (Header * h v) ((:) * fst rest)) a)

Methods

addOptionalHeader :: ResponseHeader h v -> Headers ((* ': fst) rest) a -> Headers ((* ': Header * h v) ((* ': fst) rest)) a

HasLink * sub => HasLink * ((:>) * (Header' * mods sym a) sub)

Associated Types

type MkLink ((* :> Header' * mods sym a) sub) (endpoint :: (* :> Header' * mods sym a) sub) a :: *

Methods

toLink :: (Link -> a) -> Proxy ((* :> Header' * mods sym a) sub) endpoint -> Link -> MkLink ((* :> Header' * mods sym a) sub) endpoint a

(FromHttpApiData v, BuildHeadersTo xs, KnownSymbol h) => BuildHeadersTo ((:) * (Header * h v) xs)

Methods

buildHeadersTo :: [Header] -> HList ((* ': Header * h v) xs)

type MkLink * ((:>) * (Header' * mods sym a) sub) r

type MkLink * ((:>) * (Header' * mods sym a) sub) r = MkLink * sub r