Re: [O] Babel - :export-dir and :file-ext arguments cause all blocks to emit files

[Aaron Ecay]

Hi Nicolas, hi Alex,

First of all, no issue arises with :output-dir alone.  It can be
specified as a global header arg without issue.

The situation with :file is that it (currently and at all relevant times
in the past AFAIK) implies :results file.  That is because it would be a
little strange if:

#+begin_src R :file foo.pdf
  ...
#+end_src

did not result in the output going to foo.pdf

I designed :file-ext as a direct replacement for :file.  That is, instead
of the above, one would specify:

#+name: foo
#+begin_src R :file-ext pdf
  ...
#+end_src

and get the same result.  IOW, the design was *not* for :file-ext to be
specified globally.  This perhaps could have been documented better when
it was first introduced, and I see that subsequent changes in the manual
have not made things clearer.

The change Nicolas proposes is how I would make :file-ext work if I were
writing it from scratch today, with the benefit of hindsight.  I worry
that introducing it would break org documents in the wild, but maybe it is
worth it.  Itʼs probably possible to write an org-lint check for the most
common broken case (where :file-ext is specified directly on a block, but
:results file is not.  This check would not catch a case where :file-ext
was specified via a property for a buffer/subtree of blocks all of which
are supposed to produce file results.  Such a case should be rare, but
itʼs not impossible.)  Iʼm still not 100% convinced that the breakage
would be worth it, but I suppose I would incline towards that view.

OTOH I do not think the proposed change makes sense for :file, because
it would lead to a nonsensical situation in the case of the first block
in this email.  It never has made sense to specify :file by inheritance,
so I donʼt think anything should change for that case.

-- 
Aaron Ecay