servant/servant-http-streams
2020-07-17 17:10:31 +03:00
..
src/Servant Fix servant-client with base-compat-0.11 2019-09-30 10:34:33 +03:00
test Fix typos and grammar (#1304) 2020-06-06 00:43:51 -04:00
CHANGELOG.md Update other changelogs 2020-01-23 13:43:19 +02:00
LICENSE Add servant-http-streams 2019-02-06 12:15:30 +02:00
README.lhs Add servant-http-streams 2019-02-06 12:15:30 +02:00
README.md Add servant-http-streams 2019-02-06 12:15:30 +02:00
servant-http-streams.cabal Update GHC 8.8.x versions to 8.8.3 2020-07-17 17:10:31 +03:00
Setup.hs Add servant-http-streams 2019-02-06 12:15:30 +02:00

servant-client

servant

This library lets you automatically derive Haskell functions that let you query each endpoint of a servant webservice.

Example

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeOperators #-}

import Data.Proxy
import Data.Text
import Servant.API
import Servant.HttpStreams


type Book = Text

type MyApi = "books" :> Get '[JSON] [Book] -- GET /books
        :<|> "books" :> ReqBody '[JSON] Book :> Post '[JSON] Book -- POST /books

myApi :: Proxy MyApi
myApi = Proxy

-- 'client' allows you to produce operations to query an API from a client.
postNewBook :: Book -> ClientM Book
getAllBooks :: ClientM [Book]
(getAllBooks :<|> postNewBook) = client myApi

-- the IOException happens already in withClientEnvIO
main' :: IO ()
main' = do
    let burl = BaseUrl Http "localhost" 8081 ""
    withClientEnvIO burl $ \env -> do
        res <- runClientM getAllBooks env
        case res of
            Left err -> putStrLn $ "Error: " ++ show err
            Right books -> print books

main :: IO ()
main = return ()