How to verify if a custom logo is used?

Question

How can I check whether the site is using the default theme logo or a custom logo?

When I use the Twig debug tools to dump the site_logo variable, I only get the path of the logo, which doesn't tell me if that is the default theme logo.

Answer 1

In a preprocess function, you can get that value with the following code:

$use_default = \Drupal::config('theme_machine_name.settings')->get('logo.use_default');

You can then stick that Boolean in the $variables array and make use of it in a custom Twig template.