Add conditional support for execution of elixir code blocks in org files

[ghost]

Was wondering if this might be useful, or appropriate, to add here.

Also, not sure if local sourced package not available on MELPA should be simply copied into extensions/?

I'm using it like this, in my dotspacemacs:

(defun dospacemacs/layers ()
     (elixir :variables elixir-enable-ob-elixir t)
...

and also,

(defun dotspacemacs/init ()
...
  (org-babel-do-load-languages
   'org-babel-load-languages
   '(
     ...
     (elixir . t)
     ))

PS

ob-elixir is not dependent on elixir-mode and executes an external command to evaluate code.

[syl20bnr]

Interesting proposal. We discussed a bit about this in #1159.

What I propose is to have automatic support for babel for all used layers. It is easily achievable by pushing to org-bable-load-languages in the config.el of a package (must be done conditionally though, i.e. when org layer is used, I guess we should declare a macro or function for this).

You can ask for MELPA support on the ob-elixir repo.

I'm not sure I will merge this but it is a proposal that we need to address.

cc @CestDiego @cpaulik @trishume @tuhdo

[CestDiego]

I think that if org layer is being used, and a setup-babel or some variable like that is set, then it should install it automatically.

[ghost]

@CestDiego The docs indicate that once an ob-xxx library was required, you should already be able to evaluate.

In my case, I can evaluate elixir even if I don't add it to org-babel-load-languagesorg-babel-load-languages`. I guess it's just an autoload feature provided by org-mode?

http://orgmode.org/manual/Languages.html

[CestDiego]

kek oh well this might be a thing for ob-xyz packages, but not for bundled ones, which are a lot.

[syl20bnr]

Thank you !
I was not able to merge this since the repo is gone, but I added babel support for elixir via the package ob-elixir in commit 42a33f3
Cherry-picked into develop branch, you can safely delete your branch.