ios - CoreSpotlight framework vs Spotlight Index Extension? -

corespotlight example:

https://applidium.com/en/news/ios9_search_api/

spotlight index extension example:

http://apprize.info/apple/ios_9/53.html

could explain difference between these 2 ways of spotlight usage?

the corespotlight api lets reindex app's content through cssearchableindex , cssearchableitem objects while app in foreground. (re)indexed objects available on spotlight search (a on-device search ios dashboard).

the spotlight index extension lets same while app in background/killed. implemented functions of delegate called under conditions. important in case problem occurs (re)indexed objects.

more detail here:

spotlight extension points:

• use app indexing extension point index data in app.
• use index maintenance extension point support reindexing of app data without launching app.

best