Longtable: Prevent page break after specific rows

longtable

I strongly assume that I miss the obvious.
I have a longtable and want to prevent a page break after specific rows.
After looking at the manual and looking at this question, I assumed that \\* or \nopagebreak will do the job.
However, somehow I do not get the following MWE to work as expected: Some Header C should not be "alone" at the end of a page.
What am I missing?

\documentclass{article}
% "margin = 52mm" is used to control the page break for the MWE.
\usepackage[a4paper, margin = 52mm, landscape]{geometry}
\usepackage{longtable}
\usepackage{booktabs}

\begin{document}

\begin{longtable}{p{0.25\linewidth}p{0.40\linewidth}p{0.25\linewidth}}
% Inspired by % https://tex.stackexchange.com/questions/194150
% --- First Head ---
\caption{Caption.}\\\toprule
\textbf{A} & \textbf{B} & \textbf{C}\\\toprule
\endfirsthead
% --- Other Head ---
\caption*{\textit{Continued from previous page.}}\\\toprule
\textbf{A} & \textbf{B} & \textbf{C}\\\toprule
\endhead
% --- Other Foots ---
\multicolumn{3}{r}{\textit{Continued on next page.}} \\
\endfoot
% --- Last Foot ---
\bottomrule
\endlastfoot
% --- Actual Contents ---
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\multicolumn{3}{l}{\textbf{Some Header A}}\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\multicolumn{3}{l}{\textbf{Some Header B}}\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\multicolumn{3}{l}{\textbf{Some Header C (Should not be before a page break.)}}\\*\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\multicolumn{3}{l}{\textbf{Some Header D}}\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\
\end{longtable}
 
\end{document}

Screenshot from the actual table:

Best Answer

Here is an alternative solution with longtblr environment of tabularray package:

\documentclass{article}
% "margin = 54mm" is used to control the page break for the MWE.
\usepackage[a4paper, margin = 54mm, landscape]{geometry}
\usepackage{tabularray}
\UseTblrLibrary{booktabs}

\begin{document}

\begin{longtblr}[
  caption = {Caption},
]{
  colspec = {t{0.25\linewidth}t{0.40\linewidth}t{0.25\linewidth}},
  rowhead = 1,
  row{1} = {font=\bfseries},
}
\toprule
  A & B & C \\
\toprule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\SetCell[c=3]{l}\textbf{Some Header A} & & \\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\SetCell[c=3]{l}\textbf{Some Header B} & & \\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\SetCell[c=3]{l}\textbf{Some Header C (Should not be before a page break.)} & & \\*\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
\SetCell[c=3]{l}\textbf{Some Header D} & & \\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\\midrule
a & b & c\\
\bottomrule
\end{longtblr}
 
\end{document}

Related Solutions

[Tex/LaTex] Longtable and page break

I don't think that's possible with longtable, or any other tabular environment for that matter, because the material inside the tabular cells are TeX boxes, which by definition cannot be broken.

I suggest you use parcolumns instead, which has been designed to typeset several columns next to each other for multilingual texts. Here's an example:

\documentclass{article}
\usepackage{lipsum} % Used to produce long text
\usepackage{parcolumns}

\parindent=0pt

\begin{document}
\begin{parcolumns}[colwidths={2=0.74\textwidth},rulebetween,sloppy]{2}
    \colchunk[1]{\textbf{ID}}
    \colchunk[2]{\texttt{UC\_01\_01}}
    \colplacechunks

    \colchunk[1]{\textbf{Name}}
    \colchunk[2]{Password recovery}
    \colplacechunks

    \colchunk[1]{\textbf{\textit{Macro}-UC}}
    \colchunk[2]{Registration (\texttt{UC\_01})}
    \colplacechunks

    \colchunk[1]{\textbf{Actors}}
    \colchunk[2]{\texttt{ACTOR\_02}}
    \colplacechunks

    \colchunk[1]{\textbf{Preconditions}}
    \colchunk[2]{\lipsum[2-4]}
    \colplacechunks

    \colchunk[1]{\textbf{Main flow}}
    \colchunk[2]{Some itemize list here!}
    \colplacechunks

    \colchunk[1]{\textbf{Postconditions}}
    \colchunk[2]{\lipsum[5-9]}
    \colplacechunks
\end{parcolumns}
\end{document}

[Tex/LaTex] Prevent page break after \midrule in \longtable

The problem is not confined to booktabs: Also with a standard \hline you would get a break. longtable redefines \hline so that it actually inserts two lines with a break point between them. This way a line at the bottom of a page is repeated on the top of the next page. You could define you a command which changes the penalty used by the \hline and the width temporarly:

\documentclass[12pt,a4paper]{article}

\usepackage{longtable,booktabs}

\makeatletter

\newlength\oriarrayrulewidth  
\newcount\orilowpenalty
\newcommand\nobreakmidrule{%
 \noalign{\global\oriarrayrulewidth\arrayrulewidth\relax
          \global\orilowpenalty\@lowpenalty\relax  
          \global\@lowpenalty=\numexpr-10000\relax%
          \global\arrayrulewidth\lightrulewidth\relax}
 \hline
 \noalign{\global\@lowpenalty=\orilowpenalty\relax%
          \global\arrayrulewidth\oriarrayrulewidth\relax}}

\makeatother

\begin{document}

\begin{longtable}{c}
bla \\* bla \\* bla \\* bla \\* bla \\* bla \\* bla \\*
bla \\* bla \\* bla \\* bla \\* bla \\* bla \\* bla \\*
bla \\* bla \\* bla \\* bla \\* bla \\* bla \\* bla \\*
bla \\* bla \\* bla \\* bla \\* bla \\* bla \\* bla \\*
bla \\* bla \\* bla \\* bla \\* bla \\*
bla \\*
Last line on this page \\
bla \\*\nobreakmidrule
bla \\*
bla \\* bla \\* bla \\* bla \\* bla \\* bla \\* bla \\*
\end{longtable}

\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Longtable and page break

[Tex/LaTex] Prevent page break after \midrule in \longtable

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