I happen to have the need to get the component styles in my own event subscriber (SECTION_COMPONENT_BUILD_RENDER_ARRAY). I'm getting the following PHPCS error using $event->getComponent()->get('layout_builder_styles_style'):
Call to deprecated method get() of class Drupal\layout_builder\SectionComponent: in drupal:9.1.0 and is removed from drupal:10.0.0. Additional component properties should be gotten via ::setThirdPartySetting().
Instead, I think I should be using $event->getComponent()->getThirdPartySetting('layout_builder_styles, 'style'), but the styles are not currently stored in third party setting. Instead they are stored in additional, so there is no way to access them from the previous call.
I had to write custom code to encounter this, so reproducing would probably require something like the above, although I can also just see a warning about it in my IDE, so maybe that is sufficient?
Update the logic to move storage of styles in thirdPartySetting for blocks.
Update submit handler for blocks to store styles in thirdPartySetting.
Write an update hook to move existing style instances from additional to thirdPartySetting?
None
None, I think
Moving style storage for blocks from additional to thirdPartySetting
Postponed
2.0
Code
I believe this is blocked on ✨ Support third party settings for components within a section Needs work
See also #3188763: Third party configuration for layout plugin settings →