Re: layout org-babel menu WAS: About org-babel menu

[tsd@tsdye.com (Thomas S. Dye)]

Eric Schulte <eric.schulte@gmx.com> writes:

> Torsten Wagner <torsten.wagner@gmail.com> writes:
>
>> Hi,
>>
>> for me the biggest "trouble" with babel is to remember the possible
>> keywords in the header for different languages.
>> There were a lot of ongoing syntax change which did not make it easier
>> for me to remember all this.
>> Thus a menu which is organised by languages offering all possible
>> settings for each language would be very helpful.
>> |
>> Python
>> |    |
>> |  export - code - result - both - none
>> |    |
>> |  tangle - no - yes- filename
>> |   |
>> |  result - value - output
>> |  |
>> | ...
>> |
>> ...
>>
>> Not sure how effectual this would be in a main menu. It would be
>> definitely awesome in a context menu
>>
>> That would be (copied from worg) [*] indicates cursor position
>>
>> #+NAME: factorial
>> #+BEGIN_SRC haskell [*] :results silent :exports code :var n=0
>>
>> a context menu would appear presenting all possible header arguments for haskell
>>
>> #+NAME: factorial
>> #+BEGIN_SRC haskell :results [*] :exports code :var n=0
>>
>> a context menu presenting all possible values for the header argument
>> :results in haskell
>> I guess that together with the possibility to call this menu by
>> keyboard strokes or alternatively show the same infos in the
>> minibuffer would be a great win for babel and it would make many
>> questions here on the list unnecessary.
>> Furthermore, any change or extension in the syntax for a certain
>> language would be directly reflected to the end-user. E.g., If I
>> suddenly see the menu entry :exports 3dprint, I would be curious and
>> check it out on worg and the manual ;)
>>
>> Totti
>>
>
> Hi,
>
> I've put together a first pass at such support for interactive header
> argument look up.  Please evaluate this elisp code [1] in your *scratch*
> buffer, then in an Org-mode buffer insert a code block like the
> following with the point at [*], and press tab.
>
> #+begin_src R :[*]
>   :foo
> #+end_src
>
> You should see an auto-completion list showing which header arguments
> are available and (for those with known arguments) which arguments may
> be specified.  This includes language specific header arguments, i.e.,
> the R code block above suggests about twice as many possible header
> arguments as an elisp block.  Note this "expand on tab after :" behavior
> is active on "#+headers:" lines as well.
>
> This makes use of the `org-babel-common-header-args-w-values' variable
> which holds header argument names and completions, as well as the
> org-babel-header-arg-names:lang variables.
>
> Does this seem like a good interface?
>
> Is it missing any important functionality?
>
> Best,
>
> Footnotes: 
> [1]  
> ;; Add support for completing-read insertion of header arguments after ":"
> (defun org-babel-header-arg-expand ()
>   "Call `org-babel-enter-header-arg-w-completion' in appropriate contexts."
>   (when (and (= (char-before) ?\:) (org-babel-where-is-src-block-head))
>     (org-babel-enter-header-arg-w-completion (match-string 2))))
>
> (defun org-babel-enter-header-arg-w-completion (&optional lang)
>   "Insert header argument appropriate for LANG with completion."
>   (let* ((lang-headers-var (intern (concat "org-babel-header-arg-names:" lang)))
>          (lang-headers (when (boundp lang-headers-var)
>                          (mapcar #'symbol-name (eval lang-headers-var))))
>          (headers (append (mapcar #'symbol-name org-babel-header-arg-names)
>                           lang-headers))
>          (header (org-completing-read "Header Arg: " headers))
>          (args (cdr (assoc (intern header)
>                            org-babel-common-header-args-w-values)))
>          (arg (when (and args (listp args))
>                 (org-completing-read
>                  (format "%s: " header)
>                  (mapcar #'symbol-name (car args))))))
>     (insert (concat header " " (or arg "")))
>     (cons header arg)))
>
> (add-hook 'org-tab-first-hook 'org-babel-header-arg-expand)

Hi Eric,

This is potentially much nicer than a function template.  I tried
filling out an R source code block's header arguments, but I couldn't
find a way to get :results output graphics, which I use frequently for
ggplot2 graphics.  With TAB I could see type arguments, but not
collection or handling arguments.  Is there some way to cycle through
the various completion lists?

All the best,
Tom

-- 
Thomas S. Dye
http://www.tsdye.com