We have an app that is currently on the App Store, which was built using Sencha Touch, HTML etc, with some Objective C thrown in. Now we've re- written the whole app using Xamarin iOS and Objective C.
The structure of the two apps is completely different. How can the existing app be overwritten by the new app? Some clean up code needs to be executed if it is an upgrade. I only know how to obtain the version of the new app, not sure how to check anything on the old one(version, files etc).
I'd really appreciate any pointers!
You can't check the version of the old app (unless you stored this already in the old version of the app in e.g.
NSUserDefaults - the Xamarin-based app will be able to read those). It is a good practice to store it, so if you didn't do it, do it now, so that you will be able to detect future situations in which a migration is necessary.
If you stored something in files, e.g. in the Documents directory, you can read those files as well. Unless those files were in the temporary directory, they'll be there after the upgrade.