Customizing org-mode exports

Question

So, I have been using org-mode for taking my research notes for some time now. I love how I can seamlessly export to both latex (for my papers) and html (for my blog). However,

Answer 1

Here's a standalone way that works with Org, pdflatex and MathJax at the time of this writing. Make sure the drawers (or at least the LATEXMACROS drawer) are exported (this is the default), then insert near the top of the Org file:

#+OPTIONS: toc:nil
#+DRAWERS: LATEXMACROS ...

:LATEXMACROS:
@@html:
@@
\(
\global\def\mymacro{...}
\global\def\mymacrow2args#1#2{...}
...
\)
@@html:
@@
:END:

#+TOC: headlines

This works around the following problems:

• We have to use a math environment (here \( ... \)), otherwise Org escapes the TeX syntax.

• We cannot use \newcommand, because LaTeX expects them to be in the preamble and MathJaX does not receive it. \newcommand can be used outside of the preamble, but then LaTeX (unlike MathJax) restricts the defined macros to the current math environment. We usually want to use them anywhere in the file.

• We cannot use a plain \def because it behaves like \newcommand in terms of scoping (global for MathJax, local for LaTeX). We cannot use \xdef either because MathJax does not know it.

• MathJax does not know \global but that won't prevent it from using \def which is global anyway. However, it will print a red warning for each \global in the web page. To get rid of them, we put the math environment inside an undisplayed HTML section.

• For MathJax, the macros won't be defined in time for the table of content in its default location. If you use macros in headlines and want a TOC, disable the default with #+OPTIONS: toc:nil and manually add it after the drawer with #+TOC: headlines.

Caveats:

• It's not possible to preview latex fragments which use custom macros, because the small TeX file Org build won't include our environment.

• Unlike \newcommand, \def silently replaces anything. Also, its syntax is slightly different.

• The math environment takes up some vertical space in the output of pdflatex, so we have to put it where that doesn't matter (e.g. before the first headline).

• This is probably really version dependent:

  • Org mode may get better at exporting LaTeX macros (e.g. sending them to MathJax by being smarter when parsing #+LATEX_HEADER, providing a new export option, not escaping \newcommand and putting those into a correctly handled preamble).

  • MathJax may start accepting \xdef as an alias of \def or ignoring \global (so that the HTML section trick is not needed anymore).