How to use header-args variables to fill cell values of a table

Question

I have an org-mode file as such:

* Header level 1
:header-args: :var filename="somefile.csv"

** Header level 2
:header-args: :var foo="bar"
#+begin_src emacs-lisp
foo
#+end_src

#+RESULTS:
: bar
| / |                         |       |       |      |
|   | Datetime                | Price | Attr  | Note |
|---+-------------------------+-------+-------+------|
|   | 2021-01-13 13:45:46 UTC |  12.4 |       |      |
|---+-------------------------+-------+-------+------|
#+TBLFM: @3$3=12.4
#+TBLFM: @3$4='(message "%S" foo)

I would like to be able to C-c C-c on the second formula and have "bar" written on the Attr cell for that entry.

Is this possible using header-args?

Thank you very much.

Answer 1

Assuming you meant to define header-args in properties, as I suggested in a comment, you could

• name the code block with #+name: my-name e.g.
• then in order to use the value of the code block, you can execute the code block using (org-sbe "my-name").

Something like this:

* Header level 1
  :PROPERTIES:
  :header-args:  :var foo="somefile.csv"
  :END:

** Header level 2
   :PROPERTIES:
   :header-args: :var foo="foobar"
   :END:
   
#+name: my-name
#+begin_src emacs-lisp 
foo
#+end_src

#+RESULTS: my-name
: foobar

| / |                         |       |        |      |
|   | Datetime                | Price | Attr   | Note |
|---+-------------------------+-------+--------+------|
|   | 2021-01-13 13:45:46 UTC |  12.4 | foobar |      |
|---+-------------------------+-------+--------+------|
#+TBLFM: @3$3=12.4
#+TBLFM: @3$4='(org-sbe "my-name")

Read the doc string of org-sbe with C-h f org-sbe. Note that it is the name of the code block that matters: the name of the variable foo does not (it's a local variable of the code block, so it's not visible from the outside).

EDIT: Here's a slight modification to deal with multiple variables. The assumption is that the code block returns a list of the values of the variables which are defined in the header. Then the table formula puts those values in successive rows in the third column:

* Header level 1                                                                                                
  :PROPERTIES:
  :header-args:  :var foo="somefile.csv"
  :END:

** Header level 2
   :PROPERTIES:
   :header-args: :var foo="foobar" :var bar="barfoo"
   :END:
   
#+name: my-name
#+begin_src emacs-lisp :results drawer
(list foo bar)
#+end_src

#+RESULTS: my-name
:results:
(foobar barfoo)
:end:

| / |                         |       |        |      |
|   | Datetime                | Price | Attr   | Note |
|---+-------------------------+-------+--------+------|
|   | 2021-01-13 13:45:46 UTC |  12.4 | foobar |      |
|   | 2022-01-13 13:45:46 UTC |  13.4 | barfoo |      |
|---+-------------------------+-------+--------+------|
#+TBLFM: @3$3=12.4 :: @4$3=13.4
#+TBLFM: @3$4..@>$4='(my-func (- @# 3))


** code                                                :noexport:
   #+begin_src emacs-lisp
     (defun my-func (n)
       (let ((x (read (org-sbe "my-name"))))
          (nth n x)))
   #+end_src

The my-func function basically does the "array" indexing: org-sbe returns the list as a string (unfortunately: that's a quirk of org-babel), so we invoke the lisp reader (read) to turn it back into a Lisp list and then we extract the n^th element of the list.

The function is called with the row number of the cell minus 3 to make it 0-based.