[O] new exporter drops :parameters ?

[Charles Berry]

I am trying to put together a derived backend that makes use of Src Block
:parameters attribute.

I can see that the header in a begin_src block is picked up by  

org-element-src-block-parser, as it should be when I try it interactively 

But not when I try

M-: (org-export-to-buffer 'my-latex   "*latex out*") RET

Here is an example:

=========================

#+BEGIN_SRC emacs-lisp
  (org-export-define-derived-backend my-latex e-latex
  :translate-alist ((src-block . org-rnw-src-block)))
  
  
  (defun org-rnw-src-block (src-block contents info)
    (org-element-src-block-interpreter src-block contents))
#+END_SRC

(progn
  (forward-line 3)
  (org-element-src-block-interpreter (org-element-src-block-parser) nil)) 
move cursor back after last paren and type C-x C-e
#+name: bblock
#+BEGIN_SRC R :exports code :et-cetera
rnorm(2)+1
#+END_SRC


===========================

Typing C-x C-e as above yields

"#+BEGIN_SRC R :exports code :et-cetera
  rnorm(2)+1
#+END_SRC"

but using the org-export-to-buffer line above yields

[much deleted]
#+BEGIN_SRC R
  rnorm(2)+1
#+END_SRC
% Generated by Org mode 7.8.10 in Emacs 23.3.50.1.
\end{document}

I'd really like to have access to the header elements.

AFAICS :parameters is nowhere to be found when using org-export-to-buffer.

What can I do??