Re: Include files to be used in literate programming

From: Dan Davison <davison@stats.ox.ac.uk>
To: Giorgio Valoti <giorgio_v@me.com>
Cc: emacs-orgmode@gnu.org
Subject: Re: Include files to be used in literate programming
Date: Mon, 13 Sep 2010 08:47:16 -0400	[thread overview]
Message-ID: <87fwxdhktn.fsf@stats.ox.ac.uk> (raw)
In-Reply-To: <4A6B29B6-07EA-46F0-99E9-718F93DAE558@me.com> (Giorgio Valoti's message of "Sun, 12 Sep 2010 19:02:18 +0200")

Giorgio Valoti <giorgio_v@me.com> writes:

> Hi all,
> I’ve just switched from OmniFocus and began using Org mode. But I also discovered that it can be used for literate programming and I’d like to ask if is there a way to use an included file in the tangling phase. In other words, I have a file which includes a commons.org file, like this:
>
> === commons.org contents ===
> * Variabili comuni
>   :PROPERTIES:
>   :END:
> #+SRCNAME: entity-name
> #+BEGIN_SRC :noweb yes
> nome_tabella
> #+END_SRC
>
>
> === main.org contents ===
> #+INCLUDE: "commons.org"
>
> * Sezione in SQL
>   :PROPERTIES:
>   :END:
> #+SRCNAME: sql-module
> #+BEGIN_SRC sql :tangle module.sql :noweb yes
>   select *
>   from table <<entity-name>>;
> #+END_SRC
>
> <<entity-name>> should come from the commons but it’s not.
>
> Is there a way to expand values from included files?

Hi Giorgio,

I don't know of a way currently but I agree that it is desirable. It
does seem temtping to want to use #+INCLUDE for this purpose;
however #+INCLUDE is an /export/ construct, and tangling is not
(technically at least) an Org-mode export method. So some options that
come to my mind are:

1. I am overlooking an existing way of doing this.

2. Implement #+INCLUDE when tangling, optionally or by default.

3. Implement a general way of including blocks of code from other files
   in such a way that they behave as 'normal' code blocks. This would
   have several potentially useful consequences.

4. It seems that it should be possible to get what you want by first
   using `org-export-as-org' followed by `org-babel-tangle'. However,
   `org-export-as-org' doesn't currently include #+INCLUDE'd files. I
   wonder if it should. A hack to do what you want is below (You'll be
   prompted for a file name to save the Org export buffer to.):

#+begin_src emacs-lisp
  (defun ded/org-export-as-org-to-buffer ()
    (interactive)
    (let* ((tmp-file (make-temp-file "org-tangle-with-include"))
           (org-export-preprocess-after-include-files-hook
            `((lambda () (let ((s (buffer-string)))
                           (with-temp-file ,tmp-file (insert s)))))))
      (save-window-excursion (org-export-as-html-to-buffer nil))
      (switch-to-buffer
       (get-buffer-create "*Org Org Export*"))
      (insert-file-contents tmp-file))
    (org-mode))

  (defun ded/tangle-with-include-files ()
    (interactive)
    (save-window-excursion
      (ded/org-export-as-org-to-buffer)
      (org-babel-tangle)))
#+end_src

Dan

>
> Thank you in advance.
>
> --
> Giorgio Valoti
>
>
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