Hi Xianwen,
I think the easiest way to conditionally include text in the preamble of
the document would be by including a file which can be empty sometimes, and
contain the appropriate text when needed. For example, you could have
something like this in your Org file:
#+include: ./printanswers.org
#+TITLE: Test
...
Then the following function will automatically export the file twice, one
with the \printanswers command inserted then rename the resulting file, and
export again without:
(defun org-latex-export-exams ()
(interactive)
(write-region "#+latex_header: \\printanswers" nil "printanswers.org")
(org-latex-export-to-pdf)
(rename-file (org-export-output-file-name ".pdf")
(org-export-output-file-name "-with_answers.pdf"))
(write-region "" nil "printanswers.org")
(org-latex-export-to-pdf))
You can then run M-x org-latex-export-exams to generate both files.
Hope this helps,
--Diego
On Wed, Mar 24, 2021 at 11:21 AM Xianwen Chen (陈贤文) <xianwen.c...@gmail.com>
wrote:
> 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
>
