Re: org-export-current-backend variable and org-mode 8

[Christophe Rhodes <csr21@cantab.net>]

Nicolas Goaziou <n.goaziou@gmail.com> writes:

> Christophe Rhodes <csr21@cantab.net> writes:
>
>> so that if (as I hope) org-export-current-backend makes a later
>> reappearance, my documents can work with both org-mode 7 and 8, and
>> maybe 9?  I'm hoping that the disappearance of the variable is an
>> oversight rather than intentional :-/
>
> It is intentional. I tried to reduce the number of dynamically scoped
> variables.
>
> On the other hand, hooks and filters all get back-end's name, if any, as
> an argument, which limits the need for that variable. The only missing
> part is Babel. I thought the recently introduced `by-backend' feature
> was sufficient. Isn't it the case?

The `by-backend' macro in Brett Viren's message upthread?  Personally I
don't consider that sufficient, because it feels very fragile: a simple
renaming of org-mode internal variables, or turning on lexical binding,
and the macro will no longer work.  (If you mean some other
`by-backend', I haven't seen it).

In particular, I would like to have some kind of confidence that
documents that I wrote last year will still be exportable next year with
only minor modifications necessary, and to do that I think I need to
convince you that this is valuable, enough that you are willing to
commit to some stable way of accessing the information previously held
in org-export-current-backend.

> I also thought about reintroducing `org-export-current-backend', but
> that would be redundant with hooks and filters' arguments. Removing
> these is not an option either, as that would break every hook/filter in
> the wild.

Please don't remove hooks and filters, or change their arguments!  But
please consider reintroducing org-export-current-backend; I have just
checked, and the document that I am currently editing exports to latex
and html unmodified from the org-mode 7 version, apart from some trivial
variable renamings in the elisp setup and the reintroduction through
advice of org-export-current-backend.  And although that's fairly
straightforward for me to achieve, it's a cost, and one that I have to
pay every time I want to share a reproducible research document with a
colleague who hasn't upgraded to org-mode 8 yet, maybe because some of
/their/ documents don't yet build under org-mode 8...

Best wishes,

Christophe