examples: add GS4

servant-examples/getting-started/GS4.hs

@@ -0,0 +1,63 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
+module GS4 where
+
+import Data.Aeson
+import Data.Foldable (foldMap)
+import GHC.Generics
+import Lucid
+import Network.Wai
+import Servant
+import Servant.HTML.Lucid
+
+data Person = Person
+  { firstName :: String
+  , lastName  :: String
+  , age       :: Int
+  } deriving Generic -- for the JSON instance
+
+-- JSON serialization
+instance ToJSON Person
+
+-- HTML serialization of a single person
+instance ToHtml Person where
+  toHtml p =
+    tr_ $ do
+      td_ (toHtml $ firstName p)
+      td_ (toHtml $ lastName p)
+      td_ (toHtml . show $ age p)
+
+  toHtmlRaw = toHtml
+
+-- HTML serialization of a list of persons
+instance ToHtml [Person] where
+  toHtml persons = table_ $ do
+    tr_ $ do
+      td_ "first name"
+      td_ "last name"
+      td_ "age"
+
+    foldMap toHtml persons
+
+  toHtmlRaw = toHtml
+
+persons :: [Person]
+persons =
+  [ Person "Isaac"  "Newton"   372
+  , Person "Albert" "Einstein" 136
+  ]
+
+type PersonAPI = "persons" :> Get '[JSON, HTML] [Person]
+
+personAPI :: Proxy PersonAPI
+personAPI = Proxy
+
+server :: Server PersonAPI
+server = return persons
+
+app :: Application
+app = serve personAPI server

servant-examples/getting-started/getting-started.hs

@@ -5,12 +5,14 @@ import System.Environment
 import qualified GS1
 import qualified GS2
 import qualified GS3
+import qualified GS4
 
 app :: String -> Maybe Application
 app n = case n of
   "1" -> Just GS1.app
   "2" -> Just GS2.app
   "3" -> Just GS3.app
+  "4" -> Just GS4.app
   _   -> Nothing
 
 main :: IO ()

servant-examples/servant-examples.cabal

@@ -20,7 +20,9 @@ executable getting-started
       aeson >= 0.8
     , base >= 4.7
     , either
+    , lucid
     , servant
+    , servant-lucid
     , servant-server
     , time
     , wai