chronological, recentFirst now respects metadata

Solves #111

src/Hakyll/Web/Template/List.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE TupleSections #-}
 --------------------------------------------------------------------------------
 -- | Provides an easy way to combine several items in a list. The applications
 -- are obvious:
@@ -16,9 +17,11 @@ module Hakyll.Web.Template.List
 
 
 --------------------------------------------------------------------------------
+import           Control.Monad               (liftM)
 import           Data.List                   (intersperse, sortBy)
 import           Data.Ord                    (comparing)
 import           System.FilePath             (takeBaseName)
+import           System.Locale               (defaultTimeLocale)
 
 
 --------------------------------------------------------------------------------
@@ -56,11 +59,13 @@ applyJoinTemplateList delimiter tpl context items = do
 -- | Sort pages chronologically. This function assumes that the pages have a
 -- @year-month-day-title.extension@ naming scheme -- as is the convention in
 -- Hakyll.
-chronological :: [Item a] -> [Item a]
-chronological = sortBy $ comparing $ takeBaseName . toFilePath . itemIdentifier
-
+chronological :: [Item a] -> Compiler [Item a]
+chronological = sortByM $ getItemUTC defaultTimeLocale . itemIdentifier
+                where sortByM :: (Monad m, Ord k) => (a -> m k) -> [a] -> m [a]
+                      sortByM f xs = liftM (map fst . sortBy (comparing snd)) $
+                                     mapM (\x -> liftM (x,) (f x)) xs
 
 --------------------------------------------------------------------------------
 -- | The reverse of 'chronological'
-recentFirst :: [Item a] -> [Item a]
-recentFirst = reverse . chronological
+recentFirst :: [Item a] -> Compiler [Item a]
+recentFirst i = return . reverse =<< chronological i