Cordova iOS 8.x Upgrade Guide: UIView scrollView property deprecation

[GitToTheHub]

I'm a little bit confused about the text:

The scrollView property added as a global category extension to UIView is now deprecated in Objective C code and removed entirely in Swift code. This is to prevent conflicts with other Swift classes that extend UIView and have their own scrollView properties.

It sounds like Apple deprecated something, but this only Cordova specific, or? Does this mean, that scrollView will not be accessible in the future, this means also not accessible with the selector?

[dpogue]

This is Cordova-specific.

Both WKWebView and the old UIWebView have a scrollView property that returns the underlying UIScrollView implementation. Sometimes plugins want to interact with this to do things like jumping back to the top of a page.

In old (pre-WKWebView) versions of Cordova, CDVPlugin directly exposed the UIWebView and you could call scrollView on it directly. When we moved to the pluggable webviews architecture, we could no longer expose a specific type of web view, so that property was changed to a generic UIView type.

UIView does not have a scrollView property, but to avoid breaking existing plugin code, we added a global category extension to UIView that added a public scrollView property. That extension would forward the call to the underlying web view and return the expected object.

More recently, that started causing problems in projects that use Swift UI, because the compiler sees that Cordova is defining a public scrollView property on UIView, and if another subclass of UIView has its own scrollView property that is protected or private, the compiler will throw an error about changing the visibility of the property.

For this reason, we've opted to hide/remove the scrollView extension entirely from Swift, and mark it as deprecated in Objective C because global category extensions are generally a bad idea. (IMO, plugins doing things directly to the web view's scrollable area are also generally a bad idea, so removing the shortcut that makes that easy is not a bad thing)

[GitToTheHub]

Thank you for the clarification, this is a very good explanation :)