Use the Figure Block constructor.

* It provides a specific representation for figures in the pandoc's AST.
* It uses the `SimpleFigure` pattern synonym to replace the previous
  construction:

  [Para [Image ("",[],[]) [Str "CAP2"] ("../media/rId25.jpg","fig:")]]

Author: argent0

MANUAL.txt

@@ -3171,6 +3171,17 @@ In the `context` output format this enables the use of [Natural Tables
 Natural tables allow more fine-grained global customization but come
 at a performance penalty compared to extreme tables.
 
+#### Extension: `native_figures` ####
+
+Use pandoc's native `Figure` element for content inside `<figure>` tags, in the
+case of HTML, or `figure` environments, in case of LaTeX. This, in turn, allows
+some writers to produce more accurate representations of figures. It also
+allows the use of the `Figure` element in filters, for custom figure output.
+
+This extension can be enabled/disabled for the following formats:
+
+input formats
+: `latex` `html`
 
 # Pandoc's Markdown
 

data/pandoc.lua

@@ -469,6 +469,22 @@ M.Div = M.Block:create_constructor(
   {{attr = {"identifier", "classes", "attributes"}}, "content"}
 )
 
+
+--- Creates a figure element.
+-- @function Figure
+-- @tparam      {Block,...}  content     figure block contents
+-- @tparam      Caption      caption     figure caption
+-- @tparam[opt] Attr         attr        element attributes
+-- @treturn     Block                    figure element
+M.Figure = M.Block:create_constructor(
+  "Figure",
+  function(content, caption, attr)
+    return {c = {ensureAttr(attr), caption, ensureList(content)}}
+  end,
+  {{attr = {"identifier", "classes", "attributes"}}, "caption", "content"}
+)
+
+
 --- Creates a header element.
 -- @function Header
 -- @tparam      int          level       header level

pandoc.cabal

@@ -206,6 +206,7 @@ extra-source-files:
                  test/bodybg.gif
                  test/*.native
                  test/command/*.md
+                 test/command/figures/*.md
                  test/command/*.csl
                  test/command/biblio.bib
                  test/command/averroes.bib

src/Text/Pandoc/Extensions.hs

@@ -126,6 +126,7 @@ data Extension =
     | Ext_mmd_title_block     -- ^ Multimarkdown metadata block
     | Ext_multiline_tables    -- ^ Pandoc-style multiline tables
     | Ext_native_divs             -- ^ Use Div blocks for contents of <div> tags
+    | Ext_native_figures      -- ^ Use Figure blocks for contenst of <figure> tags.
     | Ext_native_spans            -- ^ Use Span inlines for contents of <span>
     | Ext_native_numbering    -- ^ Use output format's native numbering for figures and tables
     | Ext_ntb                 -- ^ ConTeXt Natural Tables
@@ -527,6 +528,7 @@ getAllExtensions f = universalExtensions <> getAll f
   getAll "html"            = autoIdExtensions <>
     extensionsFromList
     [ Ext_native_divs
+    , Ext_native_figures
     , Ext_line_blocks
     , Ext_native_spans
     , Ext_empty_paragraphs
@@ -552,6 +554,7 @@ getAllExtensions f = universalExtensions <> getAll f
     , Ext_raw_tex
     , Ext_task_lists
     , Ext_literate_haskell
+    , Ext_native_figures
     ]
   getAll "beamer"          = getAll "latex"
   getAll "context"         = autoIdExtensions <>

src/Text/Pandoc/Lua/Marshaling/AST.hs

@@ -160,6 +160,7 @@ pushBlock = \case
   CodeBlock attr code      -> pushViaConstructor "CodeBlock" code (LuaAttr attr)
   DefinitionList items     -> pushViaConstructor "DefinitionList" items
   Div attr blcks           -> pushViaConstructor "Div" blcks (LuaAttr attr)
+  Figure attr capt blcks   -> pushViaConstructor "Figure" blcks capt (LuaAttr attr)
   Header lvl attr inlns    -> pushViaConstructor "Header" lvl inlns (LuaAttr attr)
   HorizontalRule           -> pushViaConstructor "HorizontalRule"
   LineBlock blcks          -> pushViaConstructor "LineBlock" blcks
@@ -182,6 +183,8 @@ peekBlock idx = defineHowTo "get Block value" $! do
       "CodeBlock"      -> withAttr CodeBlock <$!> elementContent
       "DefinitionList" -> DefinitionList <$!> elementContent
       "Div"            -> withAttr Div <$!> elementContent
+      "Figure"         -> (\(LuaAttr attr, capt, bs) -> Figure attr capt bs)
+                          <$!> elementContent
       "Header"         -> (\(lvl, LuaAttr attr, lst) -> Header lvl attr lst)
                           <$!> elementContent
       "HorizontalRule" -> return HorizontalRule

src/Text/Pandoc/Readers/HTML.hs

@@ -35,6 +35,7 @@ import Data.List.Split (splitWhen)
 import Data.List (foldl')
 import qualified Data.Map as M
 import Data.Maybe (fromMaybe, isJust, isNothing)
+import Data.Either (partitionEithers)
 import Data.Monoid (First (..))
 import qualified Data.Set as Set
 import Data.Text (Text)
@@ -57,7 +58,8 @@ import Text.Pandoc.Error
 import Text.Pandoc.Logging
 import Text.Pandoc.Options (
     Extension (Ext_epub_html_exts, Ext_empty_paragraphs, Ext_native_divs,
-               Ext_native_spans, Ext_raw_html, Ext_line_blocks, Ext_raw_tex),
+               Ext_native_spans, Ext_raw_html, Ext_line_blocks, Ext_raw_tex,
+               Ext_native_figures),
     ReaderOptions (readerExtensions, readerStripComments),
     extensionEnabled)
 import Text.Pandoc.Parsing hiding ((<|>))
@@ -535,24 +537,43 @@ pPara = do
     <|> return (B.para contents)
 
 pFigure :: PandocMonad m => TagParser m Blocks
-pFigure = try $ do
-  TagOpen _ _ <- pSatisfy (matchTagOpen "figure" [])
-  skipMany pBlank
-  let pImg  = (\x -> (Just x, Nothing)) <$>
-               (pInTag TagsOmittable "p" pImage <* skipMany pBlank)
-      pCapt = (\x -> (Nothing, Just x)) <$> do
-                bs <- pInTags "figcaption" block
-                return $ blocksToInlines' $ B.toList bs
-      pSkip = (Nothing, Nothing) <$ pSatisfy (not . matchTagClose "figure")
-  res <- many (pImg <|> pCapt <|> pSkip)
-  let mbimg = msum $ map fst res
-  let mbcap = msum $ map snd res
-  TagClose _ <- pSatisfy (matchTagClose "figure")
-  let caption = fromMaybe mempty mbcap
-  case B.toList <$> mbimg of
-       Just [Image attr _ (url, tit)] ->
-         return $ B.para $ B.imageWith attr url ("fig:" <> tit) caption
-       _ -> mzero
+pFigure = do
+  has_native_figures <-
+    extensionEnabled Ext_native_figures <$> getOption readerExtensions
+  if has_native_figures
+     then pNativeFigure
+     else try $ do
+        TagOpen _ _ <- pSatisfy (matchTagOpen "figure" [])
+        skipMany pBlank
+        let pImg  = (\x -> (Just x, Nothing)) <$>
+                     (pInTag TagsOmittable "p" pImage <* skipMany pBlank)
+            pCapt = (\x -> (Nothing, Just x)) <$> do
+                      bs <- pInTags "figcaption" block
+                      return $ blocksToInlines' $ B.toList bs
+            pSkip = (Nothing, Nothing) <$ pSatisfy (not . matchTagClose "figure")
+        -- res :: [(Maybe Inlines, Maybe Inlines)]
+        -- [(Just img, Nothing), (Nothing, Just caption), ...]
+        res <- many (pImg <|> pCapt <|> pSkip)
+        -- Takes the first image and the first caption, if any, drop the rest.
+        let mbimg = msum $ map fst res
+        let mbcap = msum $ map snd res -- mbcap :: Maybe Inlines
+        TagClose _ <- pSatisfy (matchTagClose "figure")
+        let caption = fromMaybe mempty mbcap
+        -- only process one image
+        case B.toList <$> mbimg of
+             Just [Image attr _ (url, tit)] ->
+               return $ B.simpleFigureWith attr caption url tit
+             _ -> mzero
+
+pNativeFigure :: PandocMonad m => TagParser m Blocks
+pNativeFigure = try $ do
+  TagOpen tag attrList <- lookAhead $ pSatisfy (matchTagOpen "figure" [])
+  --let (ident, classes, kvs) = toAttr attr
+  contents <- pInTags tag (many $ Left <$> pInTags "figcaption" block <|> (Right <$> block))
+
+  let (captions, rest) = partitionEithers contents
+  -- I should capture the caption
+  return $ B.figureWith (toAttr attrList) (Caption Nothing (B.toList (mconcat captions))) $ mconcat rest
 
 pCodeBlock :: PandocMonad m => TagParser m Blocks
 pCodeBlock = try $ do

src/Text/Pandoc/Readers/LaTeX.hs

@@ -32,6 +32,7 @@ import Data.Maybe (fromMaybe, maybeToList)
 import qualified Data.Set as Set
 import Data.Text (Text)
 import qualified Data.Text as T
+import Data.Either (partitionEithers)
 import Skylighting (defaultSyntaxMap)
 import System.FilePath (addExtension, replaceExtension, takeExtension)
 import Text.Collate.Lang (renderLang)
@@ -935,8 +936,8 @@ environments = M.union (tableEnvironments blocks inline) $
    , ("letter", env "letter" letterContents)
    , ("minipage", env "minipage" $
           skipopts *> spaces *> optional braced *> spaces *> blocks)
-   , ("figure", env "figure" $ skipopts *> figure)
-   , ("subfigure", env "subfigure" $ skipopts *> tok *> figure)
+   , ("figure", env "figure" $ skipopts *> Text.Pandoc.Readers.LaTeX.figure)
+   , ("subfigure", env "subfigure" $ skipopts *> tok *> Text.Pandoc.Readers.LaTeX.figure)
    , ("center", divWith ("", ["center"], []) <$> env "center" blocks)
    , ("quote", blockQuote <$> env "quote" blocks)
    , ("quotation", blockQuote <$> env "quotation" blocks)
@@ -1088,30 +1089,55 @@ letterContents = do
   return $ addr <> bs -- sig added by \closing
 
 figure :: PandocMonad m => LP m Blocks
-figure = try $ do
+figure = do
+  has_native_figures <-
+    extensionEnabled Ext_native_figures <$> getOption readerExtensions
+  if has_native_figures
+     then nativeFigure
+     else try $ do
+            resetCaption
+            blocks >>= addImageCaption
+
+nativeFigure :: PandocMonad m => LP m Blocks
+nativeFigure = try $ do
   resetCaption
-  blocks >>= addImageCaption
+  innerContent <- many $ try (Left <$> label) <|> (Right <$> block)
+  let content = walk go $ mconcat $ snd $ partitionEithers innerContent
+  labelResult <- sLastLabel <$> getState
+  let attr = case labelResult of
+                Just lab -> (lab, [], [])
+                _ -> nullAttr
+  captResult <- sCaption <$> getState
+  case captResult of
+    Nothing -> return $ B.figureWith attr (Caption Nothing []) content
+    Just capt -> return $ B.figureWith attr (B.caption Nothing $ B.plain capt) content
+
+  where
+  -- Remove the `Image` caption b.c. it's on the `Figure`
+  go (Para [Image attr _ target]) = Plain [Image attr [] target]
+  go x = x
 
 addImageCaption :: PandocMonad m => Blocks -> LP m Blocks
 addImageCaption = walkM go
-  where go (Image attr@(_, cls, kvs) alt (src,tit))
+  where go p@(Para [Image attr@(_, cls, kvs) _ (src, tit)])
             | not ("fig:" `T.isPrefixOf` tit) = do
           st <- getState
-          let (alt', tit') = case sCaption st of
-                               Just ils -> (toList ils, "fig:" <> tit)
-                               Nothing  -> (alt, tit)
-              attr' = case sLastLabel st of
-                        Just lab -> (lab, cls, kvs)
-                        Nothing  -> attr
-          case attr' of
-               ("", _, _)    -> return ()
-               (ident, _, _) -> do
-                  num <- getNextNumber sLastFigureNum
-                  setState
-                    st{ sLastFigureNum = num
-                      , sLabels = M.insert ident
-                                 [Str (renderDottedNum num)] (sLabels st) }
-          return $ Image attr' alt' (src, tit')
+          case sCaption st of
+            Nothing -> return p
+            Just figureCaption -> do
+              let attr' = case sLastLabel st of
+                            Just lab -> (lab, cls, kvs)
+                            Nothing  -> attr
+              case attr' of
+                   ("", _, _)    -> return ()
+                   (ident, _, _) -> do
+                      num <- getNextNumber sLastFigureNum
+                      setState
+                        st{ sLastFigureNum = num
+                          , sLabels = M.insert ident
+                                     [Str (renderDottedNum num)] (sLabels st) }
+
+              return $ SimpleFigure attr' (B.toList figureCaption) (src, tit)
         go x = return x
 
 coloredBlock :: PandocMonad m => Text -> LP m Blocks

src/Text/Pandoc/Readers/Markdown.hs

@@ -1013,19 +1013,18 @@ normalDefinitionList = do
 para :: PandocMonad m => MarkdownParser m (F Blocks)
 para = try $ do
   exts <- getOption readerExtensions
-  let implicitFigures x
-       | extensionEnabled Ext_implicit_figures exts = do
-         x' <- x
-         case B.toList x' of
-               [Image attr alt (src,tit)]
-                 | not (null alt) ->
-                    -- the fig: at beginning of title indicates a figure
-                    return $ B.singleton
-                           $ Image attr alt (src, "fig:" <> tit)
-               _ -> return x'
-       | otherwise = x
-  result <- implicitFigures . trimInlinesF <$> inlines1
-  option (B.plain <$> result)
+
+  result <- trimInlinesF <$> inlines1
+  let figureOr constr inlns =
+        case B.toList inlns of
+          [Image attr figCaption (src, tit)]
+            | extensionEnabled Ext_implicit_figures exts
+            , not (null figCaption) -> do
+                B.simpleFigureWith attr (B.fromList figCaption) src tit
+
+          _ -> constr inlns
+
+  option (figureOr B.plain <$> result)
     $ try $ do
             newline
             (mempty <$ blanklines)
@@ -1047,7 +1046,7 @@ para = try $ do
                      if divLevel > 0
                         then lookAhead divFenceEnd
                         else mzero
-            return $ B.para <$> result
+            return $ figureOr B.para <$> result
 
 plain :: PandocMonad m => MarkdownParser m (F Blocks)
 plain = fmap B.plain . trimInlinesF <$> inlines1

src/Text/Pandoc/Readers/MediaWiki.hs

@@ -201,7 +201,12 @@ para = do
   contents <- trimInlines . mconcat <$> many1 inline
   if F.all (==Space) contents
      then return mempty
-     else return $ B.para contents
+     else case B.toList contents of
+         -- For the MediaWiki format all images are considered figures
+         [Image attr figureCaption (src, title)] ->
+             return $ B.simpleFigureWith
+                 attr (B.fromList figureCaption) src title
+         _ -> return $ B.para contents
 
 table :: PandocMonad m => MWParser m Blocks
 table = do
@@ -631,7 +636,7 @@ image = try $ do
   let attr = ("", [], kvs)
   caption <-   (B.str fname <$ sym "]]")
            <|> try (char '|' *> (mconcat <$> manyTill inline (sym "]]")))
-  return $ B.imageWith attr fname ("fig:" <> stringify caption) caption
+  return $ B.imageWith attr fname (stringify caption) caption
 
 imageOption :: PandocMonad m => MWParser m Text
 imageOption = try $ char '|' *> opt

src/Text/Pandoc/Readers/Org/Blocks.hs

@@ -474,15 +474,16 @@ figure = try $ do
        figCaption = fromMaybe mempty $ blockAttrCaption figAttrs
        figKeyVals = blockAttrKeyValues figAttrs
        attr       = (figLabel, mempty, figKeyVals)
-       figTitle   = (if isFigure then withFigPrefix else id) figName
-     in
-       B.para . B.imageWith attr imgSrc figTitle <$> figCaption
-
-   withFigPrefix :: Text -> Text
-   withFigPrefix cs =
-     if "fig:" `T.isPrefixOf` cs
-     then cs
-     else "fig:" <> cs
+     in if isFigure
+           then (\c ->
+               B.simpleFigureWith
+                   attr c imgSrc (unstackFig figName)) <$> figCaption
+           else B.para . B.imageWith attr imgSrc figName <$> figCaption
+   unstackFig :: Text -> Text
+   unstackFig figName =
+       if "fig:" `T.isPrefixOf` figName
+           then T.drop 4 figName
+           else figName
 
 -- | Succeeds if looking at the end of the current paragraph
 endOfParagraph :: Monad m => OrgParser m ()