4 Replies
      Latest reply on Oct 12, 2019 2:16 AM by ArtyrRuz
      davidahouse Level 1 Level 1 (0 points)

        Looks like iOS 13 caused an issue in some of our pages we load using WKWebView. The issue is that you can't scroll vertically on the page as the screen jumps around back and forth while you try. Sometimes you can scroll slowly down the page, but eventually the screen gets stuck in a loop and the page jumps back and forth just a small amout vertically.

         

        A few more interesting notes:

        - Not all of our WKWebView screens are having this issue. Only certain ones that come from a specific source.

        - Changing to UIWebView fixes the problem.

        - This is affecting our production app version with was built with Xcode 10.3 as well as if we build with Xcode 11.

        - Same web host application works fine in Safari directly.

         

        Most likely not a native SDK issue, but some interaction of the javascript/css has problems when running in the WKWebView engine? Or could it at all be related to the modal swipe down functionality in iOS 13?

         

        I'm looking into the JS/CSS on this page to try and eliminate some possibilities. But any other things I should try/do? Any other suggestions?

        • Re: WKWebView scrolling issue on iOS 13
          davidahouse Level 1 Level 1 (0 points)

          Looks like we found the root cause somewhat. Still a bit more to fully understand it, but setting certain CSS values from javascript was causing the page to resize. This caused a continuous loop to happen which resulted in the scroll offset getting changed over and over again. AKA: Page jumps up and down.

           

          This is only a problem in iOS 13 and WKWebView. But I suspect this is a low likelyhood to happen to others. We haven't isolated the single line of code that behaves differently in iOS 13/WKWebView, but something there is different. Anyway, we found a workaround so moving on to other issues.