Add heading transclusions and rename extensions

Author: kepano

MANUAL.txt

@@ -6221,29 +6221,37 @@ or
 
     Oxygen is O~2.
 
-### Extension: `block_ids` ###
+### Extension: `wikilink_transclusions` ###
 
-Follows the [Obsidan-style block identifiers] syntax. For example add `^ref` at the end of a paragraph:
+Follows [Obsidan-style transclusions] using wikilink syntax to embed one file in another. For example to transclude the file "Title":
 
-    Text ^ref
+    ![[Title]]
 
-[Obsidan-style block identifiers]: https://help.obsidian.md/links#Link+to+a+block+in+a+note
+[Obsidan-style transclusions]: https://help.obsidian.md/embeds
+
+### Extension: `wilikink_heading_transclusions` ###
+
+Follows the [Obsidan-style heading transclusions] syntax. For example to transclude a heading within the file "Title":
 
-### Extension: `block_transclusions` ###
+    ![[Title#Heading]]
+
+[Obsidan-style heading transclusions]: https://help.obsidian.md/links#Link+to+a+heading+in+a+note
+
+### Extension: `wilikink_block_transclusions` ###
 
 Follows the [Obsidan-style block transclusions] syntax. For example to transclude block ID ^ref within the file "Title":
 
     ![[Title#^ref]]
 
 [Obsidan-style block transclusions]: https://help.obsidian.md/links#Link+to+a+block+in+a+note
 
-### Extension: `wikilink_transclusions` ###
+### Extension: `block_ids` ###
 
-Follows [Obsidan-style transclusions] using wikilink syntax to embed one file in another. For example to transclude the file "Title":
+Follows the [Obsidan-style block identifiers] syntax. For example add `^ref` at the end of a paragraph:
 
-    ![[Title]]
+    Text ^ref
 
-[Obsidan-style transclusions]: https://help.obsidian.md/embeds
+[Obsidan-style block identifiers]: https://help.obsidian.md/links#Link+to+a+block+in+a+note
 
 ### Extension: `wikilinks_title_after_pipe` ###
 

src/Text/Pandoc/Extensions.hs

@@ -58,7 +58,6 @@ data Extension =
     | Ext_blank_before_blockquote -- ^ Require blank line before a blockquote
     | Ext_blank_before_header     -- ^ Require blank line before a header
     | Ext_block_ids           -- ^ Block identifiers, used by Obsidian
-    | Ext_block_transclusion  -- ^ Block transclusions, used by Obsidian
     | Ext_bracketed_spans         -- ^ Bracketed spans with attributes
     | Ext_citations           -- ^ Pandoc/citeproc citations
     | Ext_comments            -- ^ Percent wrapped %%comments%%
@@ -144,7 +143,9 @@ data Extension =
                                      -- [[target|title]]
     | Ext_wikilinks_title_before_pipe  -- ^ Support wikilinks of style
                                        -- [[title|target]]
-    | Ext_wikilink_transclusion     -- ^ Wikilink transclusion e.g. ![[title]]
+    | Ext_wikilink_transclusions          -- ^ Wikilink transclusion e.g. ![[title]]
+    | Ext_wikilink_heading_transclusions  -- ^ Wikilink heading transclusion e.g. ![[title#heading]] in Obsidian
+    | Ext_wikilink_block_transclusions    -- ^ Wikilink block transclusions, e.g. ![[title#^id]] in Obsidian
     | Ext_xrefs_name          -- ^ Use xrefs with names
     | Ext_xrefs_number        -- ^ Use xrefs with numbers
     | Ext_yaml_metadata_block -- ^ YAML metadata block
@@ -413,7 +414,6 @@ getDefaultExtensions "obsidian"          = extensionsFromList
   [ Ext_alerts
   , Ext_autolink_bare_uris
   , Ext_block_ids
-  , Ext_block_transclusion
   , Ext_comments
   , Ext_footnotes
   , Ext_mark
@@ -423,7 +423,9 @@ getDefaultExtensions "obsidian"          = extensionsFromList
   , Ext_task_lists
   , Ext_tex_math_dollars
   , Ext_wikilinks_title_after_pipe
-  , Ext_wikilink_transclusion
+  , Ext_wikilink_transclusions
+  , Ext_wikilink_block_transclusions
+  , Ext_wikilink_heading_transclusions
   , Ext_yaml_metadata_block
   ]
 getDefaultExtensions "commonmark"      = extensionsFromList

src/Text/Pandoc/Readers/Markdown.hs

@@ -469,7 +469,7 @@ addBlockId (id', classes, kvs) st =
 
 blockTransclusion :: PandocMonad m => MarkdownParser m (F Blocks)
 blockTransclusion = try $ do
-  guardEnabled Ext_block_transclusion
+  guardEnabled Ext_wikilink_block_transclusions
   char '!'
   res <- wikilink B.linkWith
   return $ B.divWith ("", ["block-transclusion"], []) . B.para <$> res
@@ -2050,20 +2050,34 @@ wikilinkTransclusion = try $ do
         (before, after)
           | titleAfter -> (T.drop 1 after, before)
           | otherwise -> (before, T.drop 1 after)
-  let (url, blockRef) = T.break (== '#') target'
+  let (url, fragment) = T.break (== '#') target'
   guard $ T.all (`notElem` ['\n','\r','\f','\t']) url
-  if T.null blockRef
+  if T.null fragment
      then do
-       guardEnabled Ext_wikilink_transclusion
+       guardEnabled Ext_wikilink_transclusions
        currentDir <- takeDirectory . sourceName <$> getPosition
-       let filename = T.unpack url <> ".md"  -- Assume .md extension
+       let filename = T.unpack url
+       -- Support relative paths like "Folder/File" by using currentDir as base
        insertIncludedFile (fmap B.toInlines <$> parseBlocks) toSources [currentDir] filename Nothing Nothing
      else do
-       guardEnabled Ext_block_transclusion
-       currentDir <- takeDirectory . sourceName <$> getPosition
-       let filename = T.unpack url <> ".md"  -- Assume .md extension
-       let blockId = T.drop 1 blockRef  -- Remove the '^' prefix
-       insertIncludedFile (extractBlockById blockId <$> parseBlocks) toSources [currentDir] filename Nothing Nothing
+       let fragmentContent = T.drop 1 fragment  -- Remove the '#' prefix
+       if T.take 1 fragmentContent == "^"
+         then do
+           -- Block ID transclusion: ![[File#^block-id]]
+           guardEnabled Ext_wikilink_block_transclusions
+           currentDir <- takeDirectory . sourceName <$> getPosition
+           let filename = T.unpack url <> ".md"  -- Assume .md extension for block transclusion
+           let blockId = T.drop 1 fragmentContent  -- Remove the '^' prefix
+           -- Support relative paths like "Folder/File" by using currentDir as base
+           insertIncludedFile (extractBlockById blockId <$> parseBlocks) toSources [currentDir] filename Nothing Nothing
+         else do
+           -- Heading transclusion: ![[File#Heading]]
+           guardEnabled Ext_wikilink_heading_transclusions
+           currentDir <- takeDirectory . sourceName <$> getPosition
+           let filename = T.unpack url <> ".md"  -- Assume .md extension for heading transclusion
+           let headingText = fragmentContent
+           -- Support relative paths like "Folder/File" by using currentDir as base
+           insertIncludedFile (extractHeadingById headingText <$> parseBlocks) toSources [currentDir] filename Nothing Nothing
 
 note :: PandocMonad m => MarkdownParser m (F Inlines)
 note = try $ do
@@ -2391,6 +2405,40 @@ findBlockById targetId = go
         Header _ (bid, _, _) _ | bid == targetId -> Just block
         _ -> go rest
 
+-- | Extract content under a specific heading from a list of blocks
+extractHeadingById :: Text -> Blocks -> F Inlines
+extractHeadingById targetHeading blocks = 
+  case extractContentUnderHeading targetHeading (B.toList blocks) of
+    [] -> return mempty
+    content -> return $ B.toInlines $ B.fromList content
+
+-- | Extract all content under a heading until the next heading of same or higher level
+extractContentUnderHeading :: Text -> [Block] -> [Block]
+extractContentUnderHeading targetHeading = go False 0
+  where
+    go _found _level [] = []
+    go found level (block:rest) =
+      case block of
+        Header lvl _ inlines 
+          | stringify inlines == targetHeading -> 
+              -- Found target heading, start collecting content
+              block : go True lvl rest
+          | found && lvl <= level -> 
+              -- Found heading of same or higher level, stop collecting
+              []
+          | found -> 
+              -- Collecting content under target heading
+              block : go True level rest
+          | otherwise -> 
+              -- Haven't found target heading yet
+              go False level rest
+        _ | found -> 
+            -- Collecting content under target heading
+            block : go True level rest
+          | otherwise -> 
+            -- Haven't found target heading yet
+            go False level rest
+
 blockId :: PandocMonad m => MarkdownParser m (F Inlines)
 blockId = try $ do
   guardEnabled Ext_block_ids

test/command/obsidian.md

@@ -43,14 +43,28 @@ A block transclusion: ![[myfile#^my-id]]
 ```
 
 ```
-% pandoc -f obsidian-wikilink_transclusion -t native
+% pandoc -f obsidian -t native
+A heading transclusion: ![[myfile#Introduction]]
+^D
+[ Para [ Str "A" , Space , Str "heading" , Space , Str "transclusion:" , Space ] ]
+```
+
+```
+% pandoc -f obsidian-wikilink_transclusions -t native
 A wikilink transclusion: ![[my-wikilink]]
 ^D
 [ Para [ Str "A" , Space , Str "wikilink" , Space , Str "transclusion:" , Space , Str "!" , Link ( "" , [ "wikilink" ] , [] ) [ Str "my-wikilink" ] ( "my-wikilink" , "" ) ] ]
 ```
 
 ```
-% pandoc -f obsidian-block_transclusion -t native
+% pandoc -f obsidian-wikilink_heading_transclusions -t native
+A heading transclusion: ![[myfile#Introduction]]
+^D
+[ Para [ Str "A" , Space , Str "heading" , Space , Str "transclusion:" , Space , Str "!" , Link ( "" , [ "wikilink" ] , [] ) [ Str "myfile#Introduction" ] ( "myfile#Introduction" , "" ) ] ]
+```
+
+```
+% pandoc -f obsidian-wikilink_block_transclusions -t native
 A block transclusion: ![[myfile#^my-id]]
 ^D
 [ Para [ Str "A" , Space , Str "block" , Space , Str "transclusion:" , Space , Str "!" , Link ( "" , [ "wikilink" ] , [] ) [ Str "myfile#^my-id" ] ( "myfile#^my-id" , "" ) ] ]