... we dupe this Radar [1]. There is some related research and JIRA discussion here [2]
I will outline the steps you need to do below. If we don't ask for this now, enabling this feature will probably go in iOS 11, just like loading file urls in WKWebView (support was non-existent in iOS 8, added in iOS 9 with WKWebView->loadFileURL:allowingReadAccessToURL:) To allow localStorage to work with file URLs in WKWebView, Apple just needs to allow this private API "WKWebViewConfiguration-> _setAllowUniversalAccessFromFileURLs" to be public [3] ---- STEPS TO FILE A RADAR 1. Sign in to https://bugreport.apple.com with your Apple ID 2. Choose "New" from the toolbar 3. Choose "iOS SDK" 4. Copy the details from link [1] into the appropriate fields 5. Make sure you mention that it doesn't work in iOS 10 beta 3 (the latest beta as of this writing) 6. Make sure you mention the fix is to enable this private API to be public - see link [3] ---- [1] https://openradar.appspot.com/radar?id=5562982134185984 [2] https://issues.apache.org/jira/browse/CB-11524 [3] https://github.com/WebKit/webkit/blob/74c39d225ee2f6465806db45dedb8f351b56c7bd/Source/WebKit2/UIProcess/API/Cocoa/WKWebViewConfigurationPrivate.h#L52
