Added --slide-level option to override default.

This allows users to select a slide level below the first
header level with content.

Note that content under sections above the slide level will not appear
in slides (either in beamer or in HTML slide shows).

This is primarily useful for creating documents that can be made
into both slides and handouts (which contain additional content
outside the slides).

1 files changed, 9 insertions, 3 deletions

diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index adf59ae4d..5530247a2 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -115,7 +115,7 @@ pandocToHtml opts (Pandoc (Meta title' authors' date') blocks) = do
   date <- if standalone
              then inlineListToHtml opts date'
              else return mempty
-  let slideLevel = getSlideLevel blocks
+  let slideLevel = maybe (getSlideLevel blocks) id $ writerSlideLevel opts
   let sects = hierarchicalize $
               if writerSlideVariant opts == NoSlides
                  then blocks
@@ -252,15 +252,21 @@ elementToHtml slideLevel opts (Sec level num id' title' elements) = do
   modify $ \st -> st{stSecNum = num}  -- update section number
   -- always use level 1 for slide titles
   let level' = if slide then 1 else level
+  let titleSlide = slide && level < slideLevel
   header' <- blockToHtml opts (Header level' title')
-  innerContents <- mapM (elementToHtml slideLevel opts) elements
+  let isSec (Sec _ _ _ _ _) = True
+      isSec (Blk _)         = False
+  innerContents <- mapM (elementToHtml slideLevel opts)
+                   $ if titleSlide
+                        -- title slides have no content of their own
+                        then filter isSec elements
+                        else elements
   let header'' = if (writerStrictMarkdown opts ||
                      writerSectionDivs opts ||
                      writerSlideVariant opts == S5Slides)
                     then header'
                     else header' ! prefixedId opts id'
   let inNl x = mconcat $ nl opts : intersperse (nl opts) x ++ [nl opts]
-  let titleSlide = slide && level < slideLevel
   let classes = ["titleslide" | titleSlide] ++ ["slide" | slide] ++
                   ["level" ++ show level]
   let secttag  = if writerHtml5 opts