What does iOS do when an app is "Installing" and is it possible to programmatically control it?

I understand it may be unpacking some sort of compressed package into the file system (and due to the mobile nature I suppose it may be quite aggressive compression to reduce download time). But does it run any sort of preflight scripts? I suppose it does stuff like register the info.plist, add a pane in Settings.app if you've specified one, and the app's global URL and file type reception registration.

The reason why I'm interested is twofold: curiosity (would there be a way of seeing precisely what's going on? Has anyone investigated this?) and making an installation script. I'm constructing a dictionary app using Core Data (I've thought about this a lot, trust me, I want to use Core Data) and I'd like to have a way of nicely generating the Core Data store from the original X开发者_如何学GoML without degrading the user experience by having some kind of "initializing app". Furthermore I'd like to deploy the dictionary compressed and then uncompress it on the device, to keep it under the 20 mb over the air download limit.

I suppose I could generate the Core Data store on my simulator or dev phone and then add it to the bundle, though that way still seems less than neat. Hence why it would be nice for iOS to handle it for me

Anyway, thoughts?

Whatever the OS does during install, you can be certain that Apple does not offer developers any hook into the operation. There is no way to run any code of your own (install script etc.) until the user first launches your app manually. So do whatever initialization needs to be done on first launch.

The .ipa packages you submit to Apple are already compressed (they are just ZIP files with another file extension) so it should not be necessary to compress a text file yourself to stay under the 20 MB limit. Compressing it twice probably won't help much in terms of file size.