orgmode: set global BABEL parameters?

Question

I am trying to setup like the following in the top section of my .org file. But it does not work, all the parameters are not passed into the subsequent R code blocks.

 #+BABEL: :session *R* :cache yes :results output graphics :exports both :tangle yes

Doing like the following works. But it forces every code block to have :file parameter set. I don't want that because I have some code blocks which do not have graphic output.

#+PROPERTY: session *R*
#+PROPERTY: cache yes
#+PROPERTY: results graphics
#+PROPERTY: exports both
#+PROPERTY: tangle yes

How do I setup this? I prefer one-liner setup like "+BABEL:...." and customize the code blocks that I want differently.

Answer 1

One solution may be to add a PROPERTIES drawer at the heading level e.g.

:PROPERTIES:
:header-args: :session *R* :cache yes :results output graphics :exports both :tangle yes
:END:

If you do this, you cannot override individual parameters with another header-args in a PROPERTIES drawer as this overrides the whole line, but you can override indivudal parameters on the #+begin_src declaration.

Answer 2

Attempting to improve on the previous answer:

One solution is to use #+PROPERTY :header-args: for file level parameters. For example:

#+PROPERTY: :header-args:R :session *R* :cache yes :results output graphics :exports both :tangle yes

Another solution may be to add a PROPERTIES drawer at the heading level, for example:

:PROPERTIES:
:header-args:R :session *R* :cache yes :results output graphics :exports both :tangle yes
:END:

Furthermore, you can override :header-args: at lower entries via the concatenation mechanism:

* Top Level
:PROPERTIES:
:header-args:R :session *R* :cache yes :results output graphics :exports both :tangle yes
:END:

** With Overrides
:PROPERTIES:
:header-args:R+ :cache no
:END:

Similarly, each source block can contain overrides, as well.

I am constantly referring to https://org-babel.readthedocs.io/en/latest/header-args/ to aid in my babel quests.