Multiple keyboard layouts in iOS keyboard extension

Question

I am currently working on a keyboard extension for iOS, and now I am wondering how to integrate multi-layout support into system settings.

In system settings, the default keyboard en_US has an additional menu (indicated by the right arrow), where you can choose from several keyboard layouts, as you can see in the screenshot from the iOS simulator below (iOS 9.1 13B137)

Can this be done with a custom keyboard extension? I can not find any documentation on it. (This may mean that this is not possible using public APIs, or I'm too dumb to use Google.) I searched a lot on the Internet, but most of what I find is setting the keyboard locale in the Info.plist file or instructions on how to enable the system keyboard in different languages ​​(which are registered as different keyboards), which I would like to avoid.

I can see an alternative if this does not work, which will basically create several keyboard extensions in one transfer application, which include the same code base, but define different layouts. However, it would look rather ugly, clutter up the code, and people would have to include each layout separately, which, from my point of view, is not the most user-friendly way. As stated above, iOS comes with different keyboards for different languages, but I'm trying to provide multiple keyboard layouts for the same language, so this is not what I want.

Answer 1

This is not directly supported. As you said, other third-party keyboards exacerbate this problem by providing alternative keyboard layouts as a function inside the keyboard itself.

For example, Swype allows QWERTY / AZERTY / QWERTZ layout changes, long press on the spacebar.