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{-# LANGUAGE PackageImports #-}
-- Usage: a paragraph containing just [My page](!subst)
-- will be replaced by the contents of My page.
--
-- Limitations: it is assumed that My page is
-- formatted with markdown, and contains no metadata.
module Subst (plugin) where
--import "MonadCatchIO-mtl" Control.Monad.CatchIO (try)
import Control.Monad.Catch (try)
import Data.FileStore (FileStoreError, retrieve)
import Text.Pandoc (def, readMarkdown)
import Network.Gitit.ContentTransformer (inlinesToString)
import Network.Gitit.Interface
import Network.Gitit.Framework (filestoreFromConfig)
plugin :: Plugin
plugin = mkPageTransformM substituteIntoBlock
substituteIntoBlock :: [Block] -> PluginM [Block]
substituteIntoBlock ((Para [Link attr ref ("!subst", _)]):xs) =
do let target = inlinesToString ref
cfg <- askConfig
let fs = filestoreFromConfig cfg
article <- try $ liftIO (retrieve fs (target ++ ".page") Nothing)
case article :: Either FileStoreError String of
Left _ -> let txt = Str ("[" ++ target ++ "](!subst)")
alt = "'" ++ target ++ "' doesn't exist. Click here to create it."
lnk = Para [Link attr [txt] (target,alt)]
in (lnk :) `fmap` substituteIntoBlock xs
-- Right a -> let (Pandoc _ content) = readMarkdown def a
-- in (content ++) `fmap` substituteIntoBlock xs
Right a -> case readMarkdown def a of
Left err ->
let content = [Para $ [Str "Error parsing markdown in subst?"]] in
(content ++) `fmap` substituteIntoBlock xs
Right (Pandoc _ content) -> (content ++) `fmap` substituteIntoBlock xs
substituteIntoBlock (x:xs) = (x:) `fmap` substituteIntoBlock xs
substituteIntoBlock [] = return []
|
