fix #2567: add classes odd, even, and header back to table rows…

… for Pandoc >= 3.2.1

may also close #2566

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: rmarkdown
 Title: Dynamic Documents for R
-Version: 2.27.1
+Version: 2.27.2
 Authors@R: c(
     person("JJ", "Allaire", , "[email protected]", role = "aut"),
     person("Yihui", "Xie", , "[email protected]", role = c("aut", "cre"), comment = c(ORCID = "0000-0003-0645-5666")),

NEWS.md

@@ -1,8 +1,11 @@
 rmarkdown 2.28
 ================================================================================
 
+- Add classes `odd`, `even`, and `header` back to table rows for Pandoc >= 3.2.1, so tables can be styled properly (thanks, @therealgenna, #2567).
+
 - `beamer_presentation` support handling latex dependencies via the new `extra_dependencies` argument and declarations within chunks (e.g., `knitr::asis_output("", meta = list(rmarkdown::latex_dependency("longtable")))`) (thanks, @cderv, @atusy, #2478).
 
+
 rmarkdown 2.27
 ================================================================================
 

R/html_document_base.R

@@ -237,7 +237,10 @@ html_document_base <- function(theme = NULL,
     knitr = NULL,
     pandoc = pandoc_options(
       to = "html", from = NULL, args = args,
-      lua_filters = pkg_file_lua(c("pagebreak.lua", "latex-div.lua"))
+      lua_filters = pkg_file_lua(c(
+        "pagebreak.lua", "latex-div.lua",
+        if (pandoc_available("3.2.1")) "table-classes.lua"
+      ))
     ),
     keep_md = FALSE,
     clean_supporting = FALSE,

inst/rmarkdown/lua/table-classes.lua

@@ -0,0 +1,20 @@
+--[[
+Add classes 'odd' (or 'header' in table header) / 'even' to table rows
+]]
+
+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
+
+function Table (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