Missing hook to alter ChooseComponentController::list or ::componentMenu

Perhaps

/**
 * Alter the Layout Paragraphs builder.
 *
 * Implements hook_preprocess_HOOK().
 *
 * @param array $variables
 *   The variables being passed to the template.
 *
 * @see \Drupal\layout_paragraphs\Element\LayoutParagraphsBuilder::preRender()
 */
function hook_preprocess_layout_paragraphs_builder(array &$variables) {
  // Make custom alterations to the Layout Paragraphs Builder.
}

can be used for this case? Or is it too wide?

We for example need a hook to attack a further library to the "Choose a component" form.

Okay, that works (so far). But I'm still not sure, it's perfectly fine.

Here's the code, if it helps anyone:

/**
 * Implements hook_preprocess_layout_paragraphs_builder().
 */
function drowl_paragraphs_preprocess_layout_paragraphs_builder(array &$variables) {
  // Add backend library form to layout_paragraphs builder form.
  $variables['#attached']['library'][] = 'drowl_paragraphs/admin';
}

from 🐛 Library / style drowl_paragraphs/admin missing on "Choose a component" form / modal Fixed

Let's change this into a support request until we're sure, it's not expected this way.

Minor, as we have a workaround.

Seems I was wrong and the library was just loaded as a side effect of a different hook. So back to Bug report!

Okay let's clarify the title! While there is a hook for the component form, there doesn't seem to be any way to alter / attach to the component select form.

As written above, we need to attach a library for that selection, but it doesn't seem to be possible.

This is blocking 🐛 Paragraphs Settings style broken (since Claro/Gin update?) Fixed

Attaching a patch to create a hook, as I needed the functionality as well. In our case we have a "Tab" layout paragraph that lives inside "Tabs" but "Tab" shouldn't be able to be chosen from the initial list. This hook allows us to remove that.

Adding a new patch that also creates the API documentation for the hook.