Use new doctemplates, doclayout.

+ Remove Text.Pandoc.Pretty; use doclayout instead. [API change]
+ Text.Pandoc.Writers.Shared: remove metaToJSON, metaToJSON'
  [API change].
+ Text.Pandoc.Writers.Shared: modify `addVariablesToContext`,
  `defField`, `setField`, `getField`, `resetField` to work with
  Context rather than JSON values. [API change]
+ Text.Pandoc.Writers.Shared: export new function `endsWithPlain` [API
  change].
+ Use new templates and doclayout in writers.
+ Use Doc-based templates in all writers.
+ Adjust three tests for minor template rendering differences.
+ Added indentation to body in docbook4, docbook5 templates.

The main impact of this change is better reflowing of content
interpolated into templates.  Previously, interpolated variables
were rendered independently and intepolated as strings, which could lead
to overly long lines.  Now the templates interpolated as Doc values
which may include breaking spaces, and reflowing occurs
after template interpolation rather than before.

1 files changed, 21 insertions, 18 deletions

diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index de1a98173..af0780e99 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -36,6 +36,7 @@ import Data.Maybe (catMaybes, fromMaybe, isJust, isNothing, mapMaybe)
 import qualified Data.Set as Set
 import Data.String (fromString)
 import Data.Text (Text)
+import qualified Data.Text as T
 import qualified Data.Text.Lazy as TL
 import Network.HTTP (urlEncode)
 import Network.URI (URI (..), parseURIReference)
@@ -53,7 +54,8 @@ import Text.Pandoc.ImageSize
 import Text.Pandoc.Options
 import Text.Pandoc.Shared
 import Text.Pandoc.Slides
-import Text.Pandoc.Templates
+import Text.Pandoc.Templates (renderTemplate)
+import Text.DocTemplates (Context(..))
 import Text.Pandoc.Walk
 import Text.Pandoc.Writers.Math
 import Text.Pandoc.Writers.Shared
@@ -71,7 +73,6 @@ import qualified Text.Blaze.Html5 as H5
 import qualified Text.Blaze.Html5.Attributes as A5
 #endif
 import Control.Monad.Except (throwError)
-import Data.Aeson (Value)
 import System.FilePath (takeBaseName)
 import Text.Blaze.Html.Renderer.Text (renderHtml)
 import qualified Text.Blaze.XHtml1.Transitional as H
@@ -215,17 +216,17 @@ writeHtmlString' st opts d = do
        Nothing -> return $ renderHtml' body
        Just tpl -> do
          -- warn if empty lang
-         when (isNothing (getField "lang" context :: Maybe String)) $
+         when (isNothing (getField "lang" context :: Maybe Text)) $
            report NoLangSpecified
          -- check for empty pagetitle
          context' <-
             case getField "pagetitle" context of
-                 Just (s :: String) | not (null s) -> return context
+                 Just (s :: Text) | not (T.null s) -> return context
                  _ -> do
-                   let fallback = fromMaybe "Untitled" $ takeBaseName <$>
+                   let fallback = maybe "Untitled" takeBaseName $
                            lookup "sourcefile" (writerVariables opts)
                    report $ NoTitleElement fallback
-                   return $ resetField "pagetitle" fallback context
+                   return $ resetField "pagetitle" (T.pack fallback) context
          return $ renderTemplate tpl
              (defField "body" (renderHtml' body) context')
 
@@ -244,9 +245,9 @@ writeHtml' st opts d =
 pandocToHtml :: PandocMonad m
              => WriterOptions
              -> Pandoc
-             -> StateT WriterState m (Html, Value)
+             -> StateT WriterState m (Html, Context Text)
 pandocToHtml opts (Pandoc meta blocks) = do
-  metadata <- metaToJSON opts
+  metadata <- metaToContext opts
               (fmap renderHtml' . blockListToHtml opts)
               (fmap renderHtml' . inlineListToHtml opts)
               meta
@@ -298,7 +299,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
   let context =   (if stHighlighting st
                       then case writerHighlightStyle opts of
                                 Just sty -> defField "highlighting-css"
-                                              (styleToCss sty)
+                                              (T.pack $ styleToCss sty)
                                 Nothing  -> id
                       else id) $
                   (if stMath st
@@ -307,7 +308,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
                   (case writerHTMLMathMethod opts of
                         MathJax u -> defField "mathjax" True .
                                      defField "mathjaxurl"
-                                       (takeWhile (/='?') u)
+                                       (T.pack $ takeWhile (/='?') u)
                         _         -> defField "mathjax" False) $
                   defField "quotes" (stQuotes st) $
                   -- for backwards compatibility we populate toc
@@ -315,16 +316,18 @@ pandocToHtml opts (Pandoc meta blocks) = do
                   -- boolean:
                   maybe id (defField "toc") toc $
                   maybe id (defField "table-of-contents") toc $
-                  defField "author-meta" authsMeta $
-                  maybe id (defField "date-meta") (normalizeDate dateMeta) $
-                  defField "pagetitle" (stringifyHTML (docTitle meta)) $
-                  defField "idprefix" (writerIdentifierPrefix opts) $
+                  defField "author-meta" (map T.pack authsMeta) $
+                  maybe id (defField "date-meta" . T.pack)
+                    (normalizeDate dateMeta) $
+                  defField "pagetitle"
+                      (T.pack . stringifyHTML . docTitle $ meta) $
+                  defField "idprefix" (T.pack $ writerIdentifierPrefix opts) $
                   -- these should maybe be set in pandoc.hs
                   defField "slidy-url"
-                    ("https://www.w3.org/Talks/Tools/Slidy2" :: String) $
-                  defField "slideous-url" ("slideous" :: String) $
-                  defField "revealjs-url" ("reveal.js" :: String) $
-                  defField "s5-url" ("s5/default" :: String) $
+                    ("https://www.w3.org/Talks/Tools/Slidy2" :: Text) $
+                  defField "slideous-url" ("slideous" :: Text) $
+                  defField "revealjs-url" ("reveal.js" :: Text) $
+                  defField "s5-url" ("s5/default" :: Text) $
                   defField "html5" (stHtml5 st)
                   metadata
   return (thebody, context)