From 5b3bfa28f4a093a1096f628b84180165bc4cff29 Mon Sep 17 00:00:00 2001
From: Jesse Rosenthal <jrosenthal@jhu.edu>
Date: Wed, 14 Dec 2016 06:34:28 -0500
Subject: [PATCH] Class: Warn instead or erroring if we can't fetch media
If deferred media can't be fetched, we catch the error and warn
instead. We add an internal function for fetching which returns a Maybe
value, and then run catMaybes to only keep the Just's.
---
src/Text/Pandoc/Class.hs | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/src/Text/Pandoc/Class.hs b/src/Text/Pandoc/Class.hs
index 11b827aba..da9b837f7 100644
--- a/src/Text/Pandoc/Class.hs
+++ b/src/Text/Pandoc/Class.hs
@@ -102,6 +102,7 @@ import System.IO.Error
import qualified Data.Map as M
import Text.Pandoc.Error
import Data.Monoid
+import Data.Maybe (catMaybes)
class (Functor m, Applicative m, Monad m, MonadError PandocError m)
=> PandocMonad m where
@@ -188,15 +189,27 @@ instance Monoid DeferredMediaBag where
mappend (DeferredMediaBag mb lst) (DeferredMediaBag mb' lst') =
DeferredMediaBag (mb <> mb') (lst <> lst')
+
+-- the internal function for downloading individual items. We want to
+-- catch errors and return a Nothing with a warning, so we can
+-- continue without erroring out.
+fetchMediaItem :: PandocMonad m
+ => DeferredMediaPath
+ -> m (Maybe (FilePath, B.ByteString, Maybe MimeType))
+fetchMediaItem dfp =
+ (do (bs, mbmime) <- downloadOrRead Nothing (unDefer dfp)
+ return $ Just $ (unDefer dfp, bs, mbmime))
+ `catchError`
+ (const $ do warning ("Couldn't access media at " ++ unDefer dfp)
+ return Nothing)
+
fetchDeferredMedia' :: PandocMonad m => m MediaBag
fetchDeferredMedia' = do
(DeferredMediaBag mb defMedia) <- getsCommonState stDeferredMediaBag
- fetchedMedia <- mapM (\dfp -> downloadOrRead Nothing (unDefer dfp)) defMedia
+ fetchedMedia <- catMaybes <$> mapM fetchMediaItem defMedia
return $ foldr
- (\(dfp, (bs, mbMime)) mb' ->
- MB.insertMedia (unDefer dfp) mbMime (BL.fromStrict bs) mb')
- mb
- (zip defMedia fetchedMedia)
+ (\(fp, bs, mbMime) mb' -> MB.insertMedia fp mbMime (BL.fromStrict bs) mb')
+ mb fetchedMedia
fetchDeferredMedia :: PandocMonad m => m ()
fetchDeferredMedia = fetchDeferredMedia' >>= setMediaBag