Support for Lucid HTML, add static file middleware

src/Handlers.hs

@@ -3,26 +3,35 @@ module Handlers where
 import Core
 import Database
 import Logger
+import Views                              as V
 
 import qualified Data.ByteString.Char8    as C
 import Data.List
 import qualified Data.Text                as T
 import Effectful
 import Effectful.Error.Static             (Error, throwError)
+import Lucid                              (Html)
 import Servant hiding                     ((:>), throwError)
-import qualified Servant                  as S
+import Servant.HTML.Lucid
 
+-- Type synonym for common CRUD constraints like interacting with a database,
+-- logging, and the possibility to throw an error.
 type CRUD es = ( Database :> es, Logger :> es, Error ServerError :> es )
 
-rootHandler :: (Logger :> es, Error ServerError :> es) 
-            => Eff es T.Text
-rootHandler = (writeLog Info "Hit the root!") >>= \_ ->
-  return "Hello, World!"
+-- Remember to drop effect constraints you don't need!
+rootHandler :: (Logger :> es, Error ServerError :> es)
+            => Eff es (Html ())
+rootHandler = (writeLog Info "Hit the root!")
+    >>= \_ -> return V.root
 
 userListHandler :: CRUD es 
-                => Eff es [User]
-userListHandler = (writeLog Info "Selected all users!") >>= \_ ->
-  databaseRead_ "SELECT id, name FROM users"
+                => Eff es (Html ())
+userListHandler = do
+  writeLog Info "Selected all users!"
+  users <- databaseRead_ "SELECT id, name FROM users"
+  return $ V.baseDoc $ case users of
+    [] -> warning "No users found"
+    _  -> foldMap userHtml users
 
 userGetHandler :: CRUD es 
                => UserId -> Eff es User