Documented functions in Text.Hakyll.Page.

1 files changed, 22 insertions, 3 deletions

diff --git a/src/Text/Hakyll/Page.hs b/src/Text/Hakyll/Page.hs
index 7e9a76e..5b3586d 100644
--- a/src/Text/Hakyll/Page.hs
+++ b/src/Text/Hakyll/Page.hs
@@ -5,7 +5,8 @@ module Text.Hakyll.Page
       getBody,
       readPage,
       pageFromList,
-      concatPages
+      concatPages,
+      concatPagesWith
     ) where
 
 import qualified Data.Map as M
@@ -14,14 +15,21 @@ import System.FilePath
 import Data.Maybe
 import Text.Pandoc
 
+-- | A Page is basically key-value mapping. Certain keys have special
+--   meanings, like for example url, body and title.
 type Page = M.Map String String
 
+-- | Add a key-value mapping to the Page.
 addContext :: String -> String -> Page -> Page
 addContext = M.insert
 
+-- | Get the URL for a certain page. This should always be defined. If
+--   not, it will return trash.html.
 getURL :: Page -> String
-getURL context = fromMaybe "404.html" $ M.lookup "url" context
+getURL context = fromMaybe "trash.html" $ M.lookup "url" context
 
+-- | Get the body for a certain page. When not defined, the body will be
+--   empty.
 getBody :: Page -> String
 getBody context = fromMaybe "" $ M.lookup "body" context
 
@@ -44,6 +52,9 @@ markdownToHTML :: String -> String
 markdownToHTML = writeHtmlString writerOptions .
                  readMarkdown defaultParserState
 
+-- | Read a page from a file. Metadata is supported, and if the filename
+--   has a .markdown extension, it will be rendered using pandoc. Note that
+--   pages are not templates, so they should not contain $identifiers.
 readPage :: FilePath -> IO Page
 readPage path = do
     content <- readFile path
@@ -53,8 +64,16 @@ readPage path = do
         url = addExtension (dropExtension path) ".html"
     return $ addContext "url" url $ addContext "body" body $ context
 
+-- | Create a key-value mapping page from an association list.
 pageFromList :: [(String, String)] -> Page
 pageFromList = M.fromList
 
+-- | Concat the bodies of pages, and return the result.
 concatPages :: [Page] -> String
-concatPages = concat . map getBody
+concatPages = concatPagesWith "body"
+
+-- | Concat certain values of pages, and return the result.
+concatPagesWith :: String -- ^ Key of which to concat the values.
+                -> [Page] -- ^ Pages to get the values from.
+                -> String -- ^ The concatenation.
+concatPagesWith key = concat . map (fromMaybe "" . M.lookup key)