Feature request: Maintaining multiple init files with one org file

[Sven Bretfeld <sven.bretfeld@ntnu.no>]

Hi

I don't know how you guys maintain init files for different hosts. I
have one org-file with the header:

#+PROPERTY: header-args :tangle ~/.emacs

The file is synced to all my machines and produces the local init files
on each. Most configurations are shared, but some are host-specific
(e.g. font size).

Sadly export filtering does not work with the tangle function. It would
be nice to be able to do something like:

,----
| * Default Frame
| ** Office Computer                            :OFFICE:
| #+begin_src emacs-lisp
| (setq default-frame-alist '(
| 	  (font . "-PfEd-DejaVu Sans Mono-normal-normal-normal-*-26-*-*-*-m-0-iso10646-1")
| 	  (width . 102)
| 	  (height . 41))
| #+end_src
|
| ** Computer at home                           :HOME:
| #+begin_src emacs-lisp
| (setq default-frame-alist '(
| 	  (font . "-PfEd-DejaVu Sans Mono-normal-normal-normal-*-18-*-*-*-m-0-iso10646-1")
| 	  (width . 150)
| 	  (height . 50))
| #+end_src
|
| ** Laptop                                     :LAPTOP:
| #+begin_src emacs-lisp
| (setq default-frame-alist '(
| 	  (font . "-PfEd-DejaVu Sans Mono-normal-normal-normal-*-12-*-*-*-m-0-iso10646-1")
| 	  (width . 80)
| 	  (height . 30))
| #+end_src
`----

It should be clear what this is about. On the office computer you would
prepare the file headers to exclude the tags HOME and LAPTOP from being
tangled and, after saving/tangling the file, you would have a nice init
file suiting this computer. At home the same by excluding the other tags
etc.

This would save a lot of work and you would have a tidy way to maintain
all your init files without (if (string-equal (system-name) clauses.

If the noexport tag worked, it would also save a lot of time and mess
when debugging your init file in case of an error.

I don't actually understand why the developers decided not to implement
export filtering in the tangling operations. I know about the COMMENT
keyword, but the above example should make clear that this solution is
far from handy.

Maybe there is another way that escaped me so far?

All best,

Sven