Can org-babel filter code blocks?

Question

I have a general emacs.org file that I load at init time with org-babel. It's made for desktop use, and I load a bunch of IDE features, face customizations, powerline and so on. However, I also sometimes use emacs on a headless server, where such configurations don't make sense but still take time loading (especially since the server is much less powerful than my desktop). But I would still like to keep other blocks (e.g. ivy, undo-tree etc). I could just take my emacs.org and delete unnecessary blocks when putting it on my server, but now I have two different files to manage, which is a pain.

Is there a way to tell org-babel "only load these code blocks"? For example by filtering tags of headers?

Answer 1

I think this is pretty easy to do. :tangle can take no or yes, a filename, but also a lisp function. For example:

#+BEGIN_SRC bash :tangle (make-string 5 ?x)
ls -tr
#+END_SRC

Recall that header arguments can be set at different levels (for example as a +#PROPERTY under a headline) so you can have headlines for different OS, hosts, etc. Create a function that, based on the hostname, returns either emacs.el or no. When it returns no that block won't be tangled.