Open Radar

 
Summary:
If a user adds pages to their system Reading List, they are cached and the pages stored offline for quick access.
However, if a page that is downloaded is accessed through SFSafariViewController, it must be fetched again.
It would be a nicer user experience if cached pages are also loaded in SFSafariViewController when offline, allowing apps an offline-mode fallback. Ideally this would also exerted to Reading List items added programmatically, so an app may add certain URLs to Reading List, have them downloaded for offline, and the user to view these pages in the originating app when offline.

A further extension may be some way to determine if a URL has been cached offline by Reading List, though this maybe a privacy concern.

Steps to Reproduce:
Add a web page to your Reading List in Safari for iOS. Allow time for the page to be cached offline.
Open the above URL in an SFSafariViewController when offline/in airplane mode

Expected Results:
The page will be loaded with an indication that it is an offline copy (same as UI in Safari itself).

Actual Results:
The page will not be loaded and you will be presented with an error page.