How do I use hook_preprocess_page_title() on a Bootstrap subtheme? I've just discovered that Drupal 8 Bootstrap theme doesn't implement all existent hooks.
So, for example, hook_theme_suggestions_page_alter() works, but
hook_theme_suggestions_node_alter() doesn't work.

I'm interested on hook_preprocess_page_title(&amp;$variables) and I wonder if it's possible to incorporate this hook into my custom Bootstrap sub-theme. I have created the page-title.html.twig template and cleared the cache.

I saw https://drupal-bootstrap.org/api/bootstrap/docs!plugins!Preprocess.md/group/plugins_preprocess/8.x-3.x but it seems this is for extending an already existent hook in Bootstrap theme, not for adding a new one.

How do I add hook_preprocess_page_title() in a Bootstrap theme?
How do I add hook_preprocess_page_title() in a Bootstrap theme?


In your sub-theme's .theme file you add:

/*
 * Implements hook_preprocess_page_title()
 */
SUB_THEME_NAME_preprocess_page_title(&amp;$variables) {
  // your logic goes here
}