45 lines
1.1 KiB
Markdown
45 lines
1.1 KiB
Markdown
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# servant-client
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This library lets you automatically derive Haskell functions that let you query each endpoint of a *servant* webservice.
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## Example
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``` haskell
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{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE TypeOperators #-}
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import Data.Proxy
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import Data.Text
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import Servant.API
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import Servant.HttpStreams
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type Book = Text
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type MyApi = "books" :> Get '[JSON] [Book] -- GET /books
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:<|> "books" :> ReqBody '[JSON] Book :> Post '[JSON] Book -- POST /books
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myApi :: Proxy MyApi
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myApi = Proxy
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-- 'client' allows you to produce operations to query an API from a client.
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postNewBook :: Book -> ClientM Book
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getAllBooks :: ClientM [Book]
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(getAllBooks :<|> postNewBook) = client myApi
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-- the IOException happens already in withClientEnvIO
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main' :: IO ()
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main' = do
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let burl = BaseUrl Http "localhost" 8081 ""
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withClientEnvIO burl $ \env -> do
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res <- runClientM getAllBooks env
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case res of
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Left err -> putStrLn $ "Error: " ++ show err
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Right books -> print books
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main :: IO ()
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main = return ()
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```
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