BlogTest2.hs

{-# LANGUAGE OverloadedStrings #-}
import Prelude hiding (writeFile)
import Web.Scotty (scotty, get, post, html, file, param, redirect)
import Text.Blaze.Html5 (Html)
import qualified Text.Blaze.Html5 as H
import qualified Text.Blaze.Html5.Attributes as A
import Text.Blaze.Html.Renderer.Text (renderHtml)
import Text.Pandoc (Pandoc, readMarkdown, writeHtml, def)
import Data.Text.Lazy.IO (writeFile) 
import Control.Monad.Trans (liftIO)

main = scotty 3000 $ do
  get "/" $ do
    html $ renderHtml home
  post "/publish" $ do
    md <- param "markdown"
    liftIO $ publish md
    redirect "/archive"
  get "/archive" $ file "/posts/test.html"

publish :: String -> IO ()
publish md = let file = readMarkdown def md in
  writeFile "posts/test.html" $ renderHtml $ writeHtml def file

home :: Html
home = H.docTypeHtml $ do
  H.html $ do
    H.body $ do
      H.form H.! A.method "post" H.! A.action "/publish" $ do
        H.input H.! A.type_ "text" H.! A.name "markdown"
        H.input H.! A.type_ "submit"

$ runhaskell test.hs
test.hs: /home/klrr/.cabal/lib/regex-pcre-builtin-0.94.4.6.8.31/ghc-7.4.1/HSregex-pcre-builtin-0.94.4.6.8.31.o: unknown symbol utf8_table4' test.hs: test.hs: unable to load packageregex-pcre-builtin-0.94.4.6.8.31'