HTML Reader: parse figure and figcaption (#3813)

src/Text/Pandoc/Readers/HTML.hs

@@ -188,6 +188,7 @@ block = do
             , pBody
             , pDiv
             , pPlain
+            , pFigure
             , pRawHtmlBlock
             ]
   trace (take 60 $ show $ B.toList res)
@@ -553,6 +554,25 @@ pPara = do
   contents <- trimInlines <$> pInTags "p" inline
   return $ B.para contents
 
+pFigure :: PandocMonad m => TagParser m Blocks
+pFigure = do
+  TagOpen _ _ <- pSatisfy (matchTagOpen "figure" [])
+  skipMany pBlank
+  let pImg  = pOptInTag "p" pImage <* skipMany pBlank
+      pCapt = option mempty $ pInTags "figcaption" inline <* skipMany pBlank
+      pImgCapt = do
+        img <- pImg
+        cap <- pCapt
+        return (img, cap)
+      pCaptImg = do
+        cap <- pCapt
+        img <- pImg
+        return (img, cap)
+  (imgMany, caption) <- pImgCapt <|> pCaptImg
+  TagClose _ <- pSatisfy (matchTagClose "figure")
+  let (Image attr _ (url, tit)):_ = B.toList imgMany
+  return $ B.para $ B.imageWith attr url ("fig:" ++ tit) caption
+
 pCodeBlock :: PandocMonad m => TagParser m Blocks
 pCodeBlock = try $ do
   TagOpen _ attr' <- pSatisfy (matchTagOpen "pre" [])

test/command/html-read-figure.md

@@ -0,0 +1,45 @@
+```
+% pandoc -f html -t native
+<figure>
+  <img src="foo.png" title="voyage">
+  <figcaption>bar</figcaption>
+</figure>
+^D
+[Para [Image ("",[],[]) [Str "bar"] ("foo.png","fig:voyage")]]
+```
+
+```
+% pandoc -f html -t native
+<figure>
+  <figcaption>bar</figcaption>
+  <img src="foo.png" title="voyage">
+</figure>
+^D
+[Para [Image ("",[],[]) [Str "bar"] ("foo.png","fig:voyage")]]
+```
+
+```
+% pandoc -f html -t native
+<figure>
+  <img src="foo.png" title="voyage">
+</figure>
+^D
+[Para [Image ("",[],[]) [] ("foo.png","fig:voyage")]]
+```
+
+```
+% pandoc -f html -t native
+<figure>
+  <p><img src="foo.png" title="voyage"></p>
+  <figcaption>bar</figcaption>
+</figure>
+^D
+[Para [Image ("",[],[]) [Str "bar"] ("foo.png","fig:voyage")]]
+```
+
+```
+% pandoc -f html -t native
+<figure><img src="foo.png" title="voyage" alt="this is ignored"><figcaption>bar <strong>baz</strong></figcaption></figure>
+^D
+[Para [Image ("",[],[]) [Str "bar",Space,Strong [Str "baz"]] ("foo.png","fig:voyage")]]
+```