Re: [Babel] tangle - kind of macro expansion inside src blocks?

["Eric Schulte" <schulte.eric@gmail.com>]

Hello Olaf,

I've just added a new hook through which you will be able to expand
regular Org-mode style macros in code block bodies during export.  The
following org-mode snippet demonstrates its use.

First, add macro expansion to the new `org-babel-tangle-body-hook'.

#+begin_src emacs-lisp :results silent
  (add-hook 'org-babel-tangle-body-hook
            (lambda () (org-export-preprocess-apply-macros)))
#+end_src

Then define the macro.  Note: you may need to export the buffer before
tangling so that the macro definition is noticed and processed by
Org-mode.

#+MACRO: CONFIG_PARAM01 45

Then on both export and tangling the macro in the following code block
will be replaced.

#+begin_src sh :tangle yes
  echo org-mode set CONFIG_PARAMETER to: {{{CONFIG_PARAM01}}}
#+end_src

Cheers -- Eric

"Olaf.Hamann" <O.Hamann@gmx.net> writes:

> Hello all,
>
> is there a way to do so or are there plans to integrate
> a macro expansion mechanism into org-babel-tangle
> like that one org-mode already provides?
>
> #+MACRO: name replacement
> {{{name}}}
>
>
> I would like to replace config parameter in begin_src...end_src blocks.
> Change at one place in org-file shall change values in tangled code-files.
>
> I helped myself with an ugly hack in org-babel-tangle,
> so that following lines work for me at the moment.
>
> #+MACRO CONFIG_PARAM01 45
>
> #+begin_src sh :tangle file1.sh
>      echo org-mode set CONFIG_PARAMETER to: {{{CONFIG_PARAM01}}}
> #+end_src
> #+begin_src sh :tangle file2.sh
>      echo org-mode set CONFIG_PARAMETER to: {{{CONFIG_PARAM01}}}
> #+end_src
>
> (this is an example only - the language which I tangle to is not good at 
> local vars support,
> so using $CONFIG_PARAMETER inside tangled code is no solution to me)
>
> But this is no solution, so I ask whether there is already some 
> functionality to do like this,
> which will nicely fit into the aspects of different languages to be used 
> in src blocks.
> Work of org-babel-detangle will be harder when using such a macro 
> functionality
> (supported languages need inline comments, what to do with other? ).
>
> Regards,
> Olaf