org-mode File Specific Functions

Question

I am working on a literate program in org-mode. I have couple of functions in my .emacs that I use to setup a repl for the program, is it possible to move these functions to the org-mode file and they are evaluated every time the file is opened (like buffer local vars but with functions.)

Answer 1

You should be able to do this using the special eval file-local variable (emphasis mine):

Some "variable names" have special meanings in a local variables list:

• mode enables the specified major mode.
• eval evaluates the specified Lisp expression (the value returned by that expression is ignored).
• coding specifies the coding system for character code conversion of this file. See Coding Systems.
• unibyte says to load or compile a file of Emacs Lisp in unibyte mode, if the value is t. See Disabling Multibyte.

So, for example, an Org file that has this first line

# -*- eval: (message "foo"); -*-

or a block like this within the last 3000 characters of the file

# Local Variables:
# eval: (message "foo")
# End:

will evaluate (message "foo") when the file is opened.

This is a security risk, so you will be prompted when you open the file. You can use y to evaluate it once or ! to save it as a safe evaluation in your custom file and avoid future prompts.

Edit:

This is a bit awkward, but here is a way to evaluate a named source block on file load:

# -*- eval: (progn (org-babel-goto-named-src-block "foo") (org-babel-execute-src-block-maybe)) -*-

#+NAME: foo
#+BEGIN_SRC emacs-lisp :results silent
  (message "Yes, it worked")
#+END_SRC

Unfortunately I don't see any way to call the named block directly, and this way you get prompted for security two times: once for the eval and once for the code block foo.