In order to present articles while offline, the iOS app uses a custom scheme to provide permanently cached versions of files to the web view. To have that custom scheme automatically apply to all of the https URLs within the mobile-html response, they would need to be re-written as scheme-less.
Replace all https URLs (including js and css) with scheme-less equivalents. For example it would be //meta.wikimedia.org/api/rest_v1/data/css/mobile/base instead of https://meta.wikimedia.org/api/rest_v1/data/css/mobile/base
URLs that aren't https won't work offline. Is this an issue?
- Articles returned by the mobile-html endpoint have https urls replaced with their scheme-less equivalents