iOS App Store updates - Patching?

Question

When submitting an update to an app to the app store (via iTunes Connect?), is the update necessarily a whole binary? Can an update come in the form of a patch? If a second version of an app shares a lot of assets and logic from the previous version, does all that logic/resources get reinstalled wholly regardless?

Answer 1

There are no patches. It's installed as an entire read-only bundle. The old bundle is replaced with the new bundle.

Application data is retained (ie. documents folder, NSUserDefaults).

Answer 2

As everyone said before me Apple does not supply a way to hot-patch native apps, moreover it has a clear restriction - "No remote code injection".

The only thing I can add is that hybrid apps which use a javascript platform allow you to remotely replace the JS file, so you can actually change functionality remotely.(without having to release a new version) other solutions I have seen are in the gray area and allow you to run Lua Script remotely to change app functionality.

We @ Rollout.io have a different approach, we allow you to hot-patch production apps without code injection on native applications, you can read more on how the tech works here

Rollout is meant to help mobile developers solve production quality issues, hot-patching production apps, debugging production env, adding/removing analytics, etc.

Disclosure: I'm from the Rollout.io team.