Re: [babel] return file from R

["Charles C. Berry" <ccberry@ucsd.edu>]

On Thu, 17 Dec 2015, Andreas Leha wrote:

> Hi all,
>
> I think there is a bug in the handling of results of R src blocks.  What
> is the suggested way to make an R block return a link to a file?  The
> obvious way appends a newline character to the file link (which is
> broken because of that).
>
> Here is an example:
> --8<---------------cut here---------------start------------->8---
> #+NAME: TESTSRC
> #+BEGIN_SRC R :results file
>  a <- file.path("junk", "test.org")
>  a
> #+END_SRC
>
> #+RESULTS: TESTSRC
> [[file:junk/test.org
> ]]
>
> --8<---------------cut here---------------end--------------->8---


That *is* the suggested way, and it will work in (say) emacs-lisp. The 
problem for `:results value' (the default) is that a newline is added to 
the result by `org-babel-R-evaluate-external-process'.

This *might* be the fix, but I do not have time to check it thoroughly:

diff --git a/lisp/ob-R.el b/lisp/ob-R.el
index f72cd95..f660bbd 100644
--- a/lisp/ob-R.el
+++ b/lisp/ob-R.el
@@ -397,7 +397,7 @@ last statement in BODY, as elisp."
  	(org-babel-result-cond result-params
  	  (with-temp-buffer
  	    (insert-file-contents tmp-file)
-	    (buffer-string))
+	    (org-babel-chomp (buffer-string) "\n"))
  	  (org-babel-import-elisp-from-file tmp-file '(16)))
  	column-names-p)))
      (output (org-babel-eval org-babel-R-command body))))


In the meanwhile, you can work around by using `:results output' and 
wrapping the result in cat().

HTH,

Chuck