Dear Christine (and CC list),

Thank you!

On 2021-03-19 10:13, Christine Köhn wrote:

> Here is one way to do the latex part. You could pass a jobname to 
> latex.
> 
> I have this
> 
> \IfEndWith*{\jobname}{withsolution}{%
> \usepackage{todonotes}
> \printanswers
> }{\usepackage[disable]{todonotes}}
> 
> in a myexam.sty file to switch between modes (with or without solutions
> and todo notes) and use it in the latex file with
> 
> \usepackage{myexam}
> 
> You could add your own latex class to org-latex-classes and add this
> line there.
> 
> The jobname has to be passed to latex with something like -jobname
> withsolution if you want it to be with solutions. I use a Makefile for
> this purpose which calls latexmk
> 
> latexmk -pdf -pdflatex="pdflatex --interaction=errorstopmode" -use-make
> 
> and adds -jobname=$(basename $@) if asked to create a pdf ending with
> withsolution.pdf. I can send you the Makefile if you're interested.

That's very interesting way to solve the problem using LaTeX. Thank you 
for sharing this. At the moment I'm leaning more towards solving it 
using emacs lisp.

> To use the jobname from within orgmode, you'll have to change
> org-latex-pdf-process to use the jobname if needed. I think one way to
> achieve this is to add a new export backend which is derived from latex
> (see org-export-define-derived-backend) and which sets
> org-latex-pdf-process accordingly (and resets it afterwards).

Thank you again. I'm thinking of a function like following. I'm using 
comments to express the programming detail that I don't know how to do 
yet.

(deffun org-latex-export-to-pdf-exam ()
   (interactive)
   # do some emacs lisp to add \printanswers to the end of org document 
header, i.e., adding a line of #+LATEX_HEADER: \printanswers
   (org-latex-export-to-pdf)
   # do some emacs lips to move the foo.pdf to foo-with_solutions.pdf
   # do some emacs lisp to add \noprintanswers to the end of org document 
header, i.e., removing the line of #+LATEX_HEADER: \printanswers and 
adding a line of #+LATEX_HEADER: \noprintanswers
   (org-latex-export-to-pdf)
   # remove the line of #+LATEX_HEADER: \noprintanswers
)

I don't know enough emacs lisp to fill in the details here for now. 
However, I think this would be a way to do it within emacs. So each time 
I call org-latex-export-to-pdf-exam, it would export two PDF files, one 
with solutions and one without.

What do you think?

Yours sincerely,
Xianwen