Multi-line headers with longtable

Multi-line headers with longtable

[Brett Presnell]

Sorry I sent this twice.  Forgot that I was subscribed from my
member.fsf.org email address.

I have come upon a problem with export of multi-line table headers in
long (multi-page) tables.  I can't imagine that this hasn't come up
before, but I wasn't able to google up any other reports, so ...

As a simple example (using \pagebreak to reduce the number of rows
required to illustrate the problem), exporting the org table

#+attr_latex: :environment longtable
| First        | Second |
| Column       | Column |
|--------------+--------|
| a            |      1 |
| b            |      2 |
| \pagebreak c |      3 |
| d            |      4 |

to LaTeX yields

\begin{longtable}{lr}
First & Second\\
Column & Column\\
\hline
\endfirsthead
\multicolumn{2}{l}{Continued from previous page} \\

Column & Column \\

\hline
\endhead
\hline\multicolumn{2}{r}{Continued on next page} \\
\endfoot
\endlastfoot
\hline
a & 1\\
b & 2\\
\pagebreak c & 3\\
d & 4\\
\end{longtable}
\end{document}

Notice that only the "firsthead" has the multi-line table header; on the
2nd page the columns will both have the one-line header "Column" when
I/we want the full column headers on every page.

This is using org version 9.5.3 and GNU Emacs 29.0.50 (snapshot).

I think that the problem occurs in the handling of the header in
org-latex-table-row.  The 2nd row ends the header, so in the excerpted
code below it is output as =contents=, i.e., it gets inserted for the
4th %s.  Of course this means that the previous lines of the header are
missing.


	;; Special case for long tables.  Define header and footers.
	((and longtablep (org-export-table-row-ends-header-p table-row info))
	 (let ((columns (cdr (org-export-table-dimensions
			      (org-export-get-parent-table table-row) info))))
	   (format "%s
\\endfirsthead
\\multicolumn{%d}{l}{%s} \\\\
%s
%s \\\\\n
%s
\\endhead
%s\\multicolumn{%d}{r}{%s} \\\\
\\endfoot
\\endlastfoot"
		   (if booktabsp "\\midrule" "\\hline")
		   columns
		   (org-latex--translate "Continued from previous page" info)
		   (cond
		    ((not (org-export-table-row-starts-header-p table-row info))
		     "")
		    (booktabsp "\\toprule\n")
		    (t "\\hline\n"))
		   contents
		   (if booktabsp "\\midrule" "\\hline")
		   (if booktabsp "\\midrule" "\\hline")
		   columns
		   (org-latex--translate "Continued on next page" info))))
	;; When BOOKTABS are activated enforce bottom rule even when
	;; no hline was specifically marked.
	((and booktabsp (not (org-export-get-next-element table-row info)))
	 "\\bottomrule"))))))

Re: Multi-line headers with longtable

[Ihor Radchenko]

Brett Presnell <presnell@member.fsf.org> writes:

> #+attr_latex: :environment longtable
> | First        | Second |
> | Column       | Column |
> |--------------+--------|
> | a            |      1 |
> | b            |      2 |
> | \pagebreak c |      3 |
> | d            |      4 |
>
> to LaTeX yields
> ...
> Notice that only the "firsthead" has the multi-line table header; on the
> 2nd page the columns will both have the one-line header "Column" when
> I/we want the full column headers on every page.
>
> This is using org version 9.5.3 and GNU Emacs 29.0.50 (snapshot).

Confirmed.
Daniel, could you please take a look?

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: Multi-line headers with longtable

[Ihor Radchenko]

Ihor Radchenko <yantar92@gmail.com> writes:

>> This is using org version 9.5.3 and GNU Emacs 29.0.50 (snapshot).
>
> Confirmed.
> Daniel, could you please take a look?

It took a while, but...
Fixed, on main.
https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=539728840

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>