How do I prevent org-mode from executing all of the babel source blocks?

Question

I have an org file with lots of babel source blocks in it that only need to be re-executed when the code is changed.

How do I prevent org from executing all of the blocks during export? In other words, set them all to manual execution only?

I would prefer a single global option rather than having to edit each block individually.

Accommodating

Answer 1

Setting the variable org-export-babel-evaluate to nil will avoid code evaluation, but it will also cause all source block header arguments to be ignored This means that code blocks with the argument :exports none or :exports results will end up in the export. This caught me off guard.

The alternative is to use the header argument :eval no-export on a file basis and then remove that line when re-running the source code:

#+PROPERTY: HEADER-ARGS+ :eval no-export

See the docstring for org-babel-evaluate:

Switch controlling code evaluation and header processing during export. When set to nil no code will be evaluated as part of the export process and no header arguments will be obeyed. Users who wish to avoid evaluating code on export should use the header argument ‘:eval never-export’.

Sewole

This can be configured globally: (add-to-list 'org-babel-default-header-args '(:eval . "never-export")) – Reid

Answer 2

The variable org-export-babel-evaluate, if set to nil, will prevent any code from being evaluated as part of the export process. This way, only the results inserted by way of manual execution will be exported.

You can define it, and others, as a file variable by placing the following comment line at the top of your org file:

# -*- org-export-babel-evaluate: nil -*-

Calcify

org-export-babel-evaluate is depreacated. Use org-export-use-babel – Legofmutton

I set this option long ago and it troubles me how my export headers for src blocks are ignored. Turns out this global babel export control is done by ignoring all such options. Now I recommend to do (add-to-list 'org-babel-default-header-args '(:eval . "never-export")) instead. See the other answer for details. – Trellas

Answer 3

You can set the cache to yes (see http://orgmode.org/manual/cache.html). This can also be set a property line in the file to act globally. #+Property: header-args :cache yes just make sure to C-c C-c on that line to activate the property.

Unclassified

That's useful, but what if I want to completely prevent all automatic evaluation? – Accommodating

Not sure I follow. Assuming all the code has been executed at least once, then setting the property will globally prevent all re-execution. You can find it in the manual, but I believe the "official" line for a general version for the buffer is: #+PROPERTY: header-args :cache yes – Unclassified

@Unclassified what happened at least in my case is that even with cache yes, when you expertod with C-c C-e it will ask to evaluete all code blocks in your org file. – Idolum

Did you refresh the header by doing a C-c C-c in the header after adding this property? – Unclassified

Answer 4

After placing the following:

# -*- org-export-use-babel: nil;-*-

at the top of the file, and executing C-c C-c, It didn't work for me. The variable's value is not set accordingly.

But the following:

#+BIND: org-export-use-babel nil

with an application of C-c C-c works as expected.

I found the answer here: http://joelmccracken.github.io/entries/org-mode-specifying-document-variables-and-keywords/

There are probably some changes in emacs 26, which I'm using.

Faceless

The documentation of org-export-use-babel in emacs 26.1 says Users who wish to avoid evaluating code on export should use the header argument ‘:eval never-export’. – Runic

> For this change to take effect revisit file using M-x revert-buffer , see #20033967 – Beseem

Answer 5

This means that code blocks with the argument :exports none or :exports results will end up in the export. This caught me off guard.

one way to avoid this is hiding it in the css, you can inspect the code block in the html and see the classes there

Then you can just

.src {
  display: none;
}

or other specific class

Sensate