Is there any
hook_preprocess_block or any other way to I can add my custom classes to all blocks of a custom kind?Or in the other words:
How can I target all blocks of custom kind?
For example I want to add
search class to all search blocks (or target all search blocks in my theme by using default auto-generated classes by Drupal core if it be available), or add
user-login class to all user login blocks and so forth in my theme without any need to create a template for every block.