Use doctemplates 0.3, change type of writerTemplate.

* Require recent doctemplates.  It is more flexible and
  supports partials.
* Changed type of writerTemplate to Maybe Template instead
  of Maybe String.
* Remove code from the LaTeX, Docbook, and JATS writers that looked in
  the template for strings to determine whether it is a book or an
  article, or whether csquotes is used. This was always kludgy and
  unreliable.  To use csquotes for LaTeX, set `csquotes` in your
  variables or metadata. It is no longer sufficient to put
  `\usepackage{csquotes}` in your template or header includes.
  To specify a book style, use the `documentclass` variable or
  `--top-level-division`.
* Change template code to use new API for doctemplates.

1 files changed, 4 insertions, 7 deletions

diff --git a/src/Text/Pandoc/Writers/Custom.hs b/src/Text/Pandoc/Writers/Custom.hs
index 5e2f3a583..7d85a262d 100644
--- a/src/Text/Pandoc/Writers/Custom.hs
+++ b/src/Text/Pandoc/Writers/Custom.hs
@@ -25,7 +25,6 @@ import Data.Typeable
 import Foreign.Lua (Lua, Pushable)
 import Text.Pandoc.Class (PandocIO)
 import Text.Pandoc.Definition
-import Text.Pandoc.Error
 import Text.Pandoc.Lua (Global (..), LuaException (LuaException),
                         runLua, setGlobals)
 import Text.Pandoc.Lua.Util (addField, dofileWithTraceback)
@@ -109,12 +108,10 @@ writeCustom luaFile opts doc@(Pandoc meta _) = do
   let (body, context) = case res of
         Left (LuaException msg) -> throw (PandocLuaException msg)
         Right x -> x
-  case writerTemplate opts of
-       Nothing  -> return $ pack body
-       Just tpl ->
-         case applyTemplate (pack tpl) $ setField "body" body context of
-              Left e  -> throw (PandocTemplateError e)
-              Right r -> return r
+  return $
+    case writerTemplate opts of
+       Nothing  -> pack body
+       Just tpl -> renderTemplate tpl $ setField "body" body context
 
 docToCustom :: WriterOptions -> Pandoc -> Lua String
 docToCustom opts (Pandoc (Meta metamap) blocks) = do