add back odd, even, header classes from older pandoc in normalize processing

Author: cderv

src/resources/filters/main.lua

@@ -98,6 +98,7 @@ import("./quarto-finalize/typst.lua")
 
 import("./normalize/flags.lua")
 import("./normalize/normalize.lua")
+import("./normalize/pandoc-tables.lua")
 import("./normalize/parsehtml.lua")
 import("./normalize/extractquartodom.lua")
 import("./normalize/astpipeline.lua")

src/resources/filters/normalize/astpipeline.lua

@@ -22,6 +22,9 @@ function quarto_ast_pipeline()
     }
   end
   return {
+    -- identify pandoc table
+    { name = "normalize-pandoc-table", filter = pandoc_tables() },
+
     { name = "normalize-table-merge-raw-html", filter = table_merge_raw_html() },
 
     -- this filter can't be combined with others because it's top-down processing.

src/resources/filters/normalize/pandoc-tables.lua

@@ -0,0 +1,26 @@
+-- pandoc-tables.lua
+-- Copyright (C) 2024 Posit Software, PBC
+
+-- Add back classes 'odd', (or 'header' in table header) / 'even' to table rows
+-- They were removed in pandoc 3.2.1 but are useful for styling pandoc processed tables
+-- Quarto detects .odd class 
+function pandoc_tables()
+  local function add_odd_even (rows, odd)
+    odd = odd or 'odd'
+    for rownum, row in ipairs(rows) do
+      row.classes:insert((rownum % 2) == 0 and 'even' or odd)
+    end
+    return rows
+  end
+
+  return {
+    Table = function (tbl)
+      add_odd_even(tbl.head.rows, 'header')
+      for _, tblbody in ipairs(tbl.bodies) do
+        add_odd_even(tblbody.body)
+      end
+      add_odd_even(tbl.foot.rows)
+      return tbl
+    end
+  }
+end