Highlight anything in LaTeX article

Question

I'm looking for a package/command that will highlight anything I wrap with it. Currently the closest thing I've found is soul but it has many shortcomings:

• No sectioning highlighting
• No automatic footnotes highlighting
• No \cite highlighting unless wrapped in an \mbox{}
• No \citep highlighting

Here's an example article where these points can be seen:

\documentclass{article}
\usepackage{hyperref}
\hypersetup{colorlinks=true, urlcolor=blue, citecolor=cyan, pdfborder={0 0 0},}
\usepackage{soul}
\usepackage{natbib}
\bibliographystyle{plainnat}

\begin{document}

\section{\hl{Title of a section}}

This is a line with no highlighting done.\\
\hl{This is a line where a citation \citep{Knuth86} appears.}
\hl{This is a line with a footnote\footnote{And this is the footnote that should also be automatically highlighted.} which I want highlighted.}

\bibliography{biblio}

\end{document}

where the biblio.bib file looks like:

@ARTICLE{Knuth86,
   author = {Knuth, D. E.},
    title = "{The TeXbook}",
    year = 1986,
}

If you try to compile it with the usual:

pdflatex "%f" && bibtex "%e" && pdflatex "%f" && pdflatex "%f"

command, it will fail for all the reasons I gave above. Isn't there something that just works?

---

Edit

The accepted answer comes close but after finding out about latexdiff (http://www.ctan.org/pkg/latexdiff) I actually switched to using that app instead of manually highlighting text.

Answer 1

This is only a partial solution and it doesn't really work across linebreaks well, but if you replace the highlight commands with

\usepackage{tcolorbox}
\newtcbox{\hl}[1][yellow]{on line, arc=7pt,colback=#1!10!white,colframe=#1!50!black,
  before upper={\rule[-3pt]{0pt}{10pt}},boxrule=1pt, boxsep=0pt,left=6pt,
  right=6pt,top=2pt,bottom=2pt}

then I think that the highlighting almost works the way that the OP wants it to:

The main issue is that the \footnote does not appear at all. (The OP might also complain about \citep but as the package specifications for this seem to be missing I just used \usepackage[numbers]{natbib} and carried on.)

You can get the footnote to display properly, with the required highlighting, by manually using \footnotemark and \footnotetext:

\hl{This is a line with a footnote\footnotemark which I want highlighted.}
\footnotetext{\hl{And this is the footnote that should also be 
      automatically highlighted.}}

This now produces the missing footnote:

The OP no doubt would prefer the footnotes to be cared for automatically. I think that this should be possible to arrange, although multiple footnotes in a section of highlighted text might cause problems. I don't have time to do this now but if no one else has found a solution I will try and look at this tomorrow.

Answer 2

You need to be careful of stomach commands in section titles, use the optional argument. This works. You also have an issue with \citep{} from "natbib", which you missed from your MWE.

\documentclass{article}
\usepackage{hyperref}
\hypersetup{colorlinks=true, urlcolor=blue, citecolor=cyan, pdfborder={0 0 0},}
\usepackage{soul}

\begin{document}

\section[title of section]{\hl{Title of a section}}

This is a line with no highlighting done.\\
\hl{This is a line where a citation \protect\cite{Knuth86} appears.}
\hl{This is a line with a footnote\footnote{\protect\hl{And this is the footnote that should also be automatically highlighted.}} which I want highlighted.}

\begin{thebibliography}{1}
\bibitem{Knuth86} D.E. Knuth, The TeXbook, 1986
\end{thebibliography}

\end{document}

Check this article for some very goods tips, about hyperref's commands.