Org babel support

[CestDiego]

I wonder if there will be a way of configuring what packages to add to babel. Cannot think of any. Shall we just add all of the packages we can?

[cpaulik]

I would not enable all of those layers by default. Why not explain in the Readme how to enable them in the .spacemacs? Another way would be to introduce a variable that can be set in .spacemacs so that the users do not have to concern themselves with lazy loading issues.

[syl20bnr]

So what do we do about this ?

What is the impact of adding a bunch of language, does it slow down something ? I yes the we should enable less languages.

An approach would be to enable the languages that are used by the user and let her add additional languages in her dotfile. Ideally, the user should have just to add symbols to a variable.
Auto-loading of used languages may be confusing though.

A variable in the dotfile seems the best approach. Could be named org-enable-babel-languages and could be passed with :variables keyword when defining the used layers list.

[CestDiego]

Being honest I don't see much overhead of adding a bunch of languages. Although I do think that at least the languages the user has installed should be suggested as default in org-babel.

Another approach could be that each language layer had a :variable org-babel-support but that is WAY messier.

I'm fine with the first approach, but I do not know how to implement it :( Some guidelines would be appreciated. thanks :)

[syl20bnr]

Mmmmh if a language is added, the major-mode is required right ? So the user has to enable the corresponding layer ?

[CestDiego]

You can see the requirements here http://orgmode.org/worg/org-contrib/babel/languages.html.
Sometimes it's a layer, sometimes it's a program that needs to be in the path :( I think that maybe just giving instructions on how to do it in the readme would be ok.

[syl20bnr]

Indeed we go for the README solution for now.

I like the idea to enable automatically the support of babel for used layers though. It could be easily achievable by creating a function that any layer can use in its config.el file to add itself to the list of babel activated packages.
Or even in the init function of the required package.

[CestDiego]

ok this works for me

On Sat, Apr 25, 2015 at 2:01 AM, Sylvain Benner notifications@github.com
wrote:

Indeed we go for the README solution for now.

I like the idea to enable automatically the support of babel for used
layers though. It could be easily achievable by creating a function that
any layer can use in its config.el file to add itself to the list of
babel activated packages.

—
Reply to this email directly or view it on GitHub
#1159 (comment).

[syl20bnr]

In fact to support it very cleanly we should add org in the package list of a layer and create a function <layer>/post-init-org where we activate the language.

[ghost]

I'm not sure how necessary it is, in fact. 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

PS Sorry for the double commenting... meant to post at #1918

[CestDiego]

@usharf can you SPC h d v org-babel-load-languages? elixir should be there even though you haven't setted it up, and the reason is that most ob-xxx packages automatically append to that variable when set.

[ghost]

@CestDiego Not this one, I just checked and also looked at the source... but even so, no problem evaluating elixir code blocks once ob-elixir has been require, like noted.

[robbyoconnor]

@CestDiego this is invalid -- it's against master -- should prolly close it :P

[CestDiego]

oh man...The times I didn't know how to PR xD

[robbyoconnor]

Add this in a new PR <3 - I need it in my life <3

[CestDiego]

I thought this was enabled by default in Spacemacs? D:

[CestDiego]

I'm planning on reviving org babel. @syl20bnr Are there any more pointers to take in mind?

[syl20bnr]

@CestDiego Good idea, I started to use it for literate devops and I had to add some initialization stuff in my user-config, would be nice to support it out of the box.
I guess it could be automatically enabled given that org layer is used. This comment is a good pointer to start with: #1159 (comment)

[CharlesHD]

I was wondering about that. Should we do like in that commit for every lang layer supported by babel ? 931652b
If it's the case I can PR that (a PR by layer or a global layer ?).

[d12frosted]

Using <layer>/post-init-org is indeed good solution. Use only what is used 😸

@CharlesHD I believe it should be one PR.

---

I see two ways of enabling babel for supported languages. First one is to manually create post-init-org functions in all layers that support it. Second is to have a list of supported layers (languages) in org layer and just call spacemacs|use-package-add-hook for every layer in that list that is enabled.

I like second solution as it results in no code duplication. On the other hand it's breaking encapsulation a little bit. I mean, we let org layer to know about other layers. And more over - it creates post-init hook, which might sound really bad for some cases.

What do you guys think?

[cpaulik]

@d12frosted If we would want to centralize it shouldn't it be enough to just call (add-to-list 'org-babel-load-languages... for each enabled layer in the org config? Why is there a need to use use-package-add-hook?

[d12frosted]

Ah. Good point, there is no need to make use-package hook. Just add to list. But yeah, only for enabled layers.

[CharlesHD]

If we would want to centralize it shouldn't it be enough to just call (add-to-list 'org-babel-load-languages... for each enabled layer in the org config?

Is there a mechanism to get all current active layers ?

[d12frosted]

@CharlesHD AFAIK there is no function to get all active layers, but you can easily fetch one using configuration-layer/get-layers-list and configuration-layer/layer-usedp - (-filter #'configuration-layer/layer-usedp (configuration-layer/get-layers-list)).

P. S. -filter is part of dash.el