Add Android and iOS wheels

[timrid]

It would be nice if wheels were built for Android and iOS.

PEP 738 added Android and PEP 730 added iOS as official platforms since Python 3.13. iOS has been supported since cibuildwheel v3.0.0, and Android since v3.1.0. This should make it very easy to support wheels for these platforms.

[davidism]

Could you give specific examples of why would it be very nice? How are you using MarkupSafe on these platforms?

[timrid]

My intention is not to use markupsafe directly, but it is the only binary dependency of, for example, jinja2 or flask. I currently don't have any specific projects in which I use jinja2 or flask in an Android or iOS app, but I think it's quite realistic that I or others will need them in the future. E.g. to run a flask app in a WebView.

To build an Android or iOS app, I use the Beeware tool briefcase. jinja2 already works on Android with Python 3.13, but only because markupsafe is in the chaquopy index and briefcase is based internally on chaquopy. For iOS, there is also a separate index with iOS-specific wheels, but markupsafe is not yet added here, which is why it is not yet usable on iOS.

However, the Beeware team's plan is that these separate indexes will no longer be needed in the long term, so they have put a lot of work into cibuildwheel to make building Android and iOS wheels as easy as possible. So far, there are very few libraries with binary dependencies for Android and iOS in the official index at pypi, but the number of libraries is slowly growing (here is an overview of all currently available mobile wheels).