add an example to show how to apply a WAI middleware

This commit is contained in:
Alp Mestanogullari 2015-04-24 12:37:33 +02:00
parent ac73b825f0
commit e371fb886f
2 changed files with 65 additions and 0 deletions

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@ -27,3 +27,17 @@ executable hackage
, transformers , transformers
hs-source-dirs: hackage hs-source-dirs: hackage
default-language: Haskell2010 default-language: Haskell2010
executable wai-middleware
main-is: wai-middleware.hs
build-depends:
aeson >= 0.8
, base >= 4.7
, servant
, servant-server
, text
, wai
, wai-extra
, warp
hs-source-dirs: wai-middleware
default-language: Haskell2010

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@ -0,0 +1,51 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
import Data.Aeson
import Data.Text
import GHC.Generics
import Network.Wai
import Network.Wai.Handler.Warp
import Network.Wai.Middleware.RequestLogger
import Servant
data Product = Product
{ name :: Text
, brand :: Text
, current_price_eur :: Double
, available :: Bool
} deriving (Eq, Show, Generic)
instance ToJSON Product
products :: [Product]
products = [p1, p2]
where p1 = Product "Haskell laptop sticker"
"GHC Industries"
2.50
True
p2 = Product "Foldable USB drive"
"Well-Typed"
13.99
False
type SimpleAPI = Get '[JSON] [Product]
simpleAPI :: Proxy SimpleAPI
simpleAPI = Proxy
server :: Server SimpleAPI
server = return products
-- logStdout :: Middleware
-- i.e, logStdout :: Application -> Application
-- serve :: Proxy api -> Server api -> Application
-- so applying a middleware is really as simple as
-- applying a function to the result of 'serve'
app :: Application
app = logStdout (serve simpleAPI server)
main :: IO ()
main = run 8080 app