[O] Tangle only code block body

[Ista Zahn]

Hi all,

Is there a way to tangle just the body of code blocks, without any header 
argurments? For example when I tangle this file

##### begin example #####

* test
#+name: testplot
#+begin_src R :results output graphics :file tmp.png :tangle tmp.R
  plot(1:10)
#+end_src

##### end example #####

I get

png(filename="tmp.png")
plot(1:10)
dev.off()

but I want just

plot(1:10)


I've tried removing the %flag setting in org-babel-exp-code-template but it 
didn't seem to have any effect. 

Thanks for any pointers,

Ista