In which case we will use State API ? Instead of UserData API ?
Some Use cases where we will use State API ?
Some use cases where we will UserData API?
Is there any difference apart from the following?
- Information stored is not configuration that should be exported.
Real world examples for both. Is any popular contrib or core modules using this concepts(except user module) ?
You find real world examples for State API in the
key_value table under the collection
comment.maintain_entity_statistics field.field.deleted install_time locale.translation_last_checked search_api.index.default_index.has_reindexed system.cron_last system.maintenance_mode update.last_check webform.version
The first part of the name is usually the module. In these examples they are core and the popular contrib modules Search API and Webform.
In contrast UserData API is obviously specific to the user, not the entire system. You would use it for data you don't want to store in a user field. Because it is easy to add user fields in code and config this service is rarely used in Drupal 8+.