+1 to this question. I have the exact same annoyance (would also be nice to
do some threading so it doesn't lock up emacs for a few seconds)

On Fri, Dec 4, 2020 at 2:28 PM Pankaj Jangid <pankaj@codeisgreat.org> wrote:

> Mirko Vukovic <mirko.vukovic@gmail.com> writes:
>
> > My current workflow is
> >
> >    1. Enter edit buffer (C-c ')
> >    2. Perform edits in the window
> >    3. Exit edit mode (C-c ')
> >    4. Evaluate code (C-c C-c)
> >    5. Monitor changes to resulting png file
> >
> > I would prefer instead to skip step 3, and evaluate the code from within
> > the edit mode.
> >
> > Is it possible to execute code from the edit buffer?
>
> 1. When I enter the edit mode (C-c ') it connects to plantuml server
> (that I don't like), and produces the error that you have specified:
> "Wrong type argument: stringp, nil".
>
> 2. Pressing C-c C-c in the edit buffer opens up plantuml preview but it
> gives some error: "The plugin you are using seems to generate a bad
> URL".
>
> I am on Emacs 28.x and default org 9.3.
>
>