Using environmentObject in watchOS

Question

I am trying to use environmentObject in a watchOS6 app to bind my data model to my view.

I have created a simple, stand-alone Watch app in Xcode 11.

Answer 1

You can use type erasure, AnyView in the case of SwiftUI View.

I would refactor WKHostingController to return AnyView.

This seems to compile fine on my end.

class HostingController : WKHostingController<AnyView> {
    override var body: AnyView {
        return AnyView(ContentView().environmentObject(DataModel()))
    }
}

Answer 2

Adding to Matteo's awesome answer,

If you want to use delegate then use like this:

class HostingController : WKHostingController<AnyView> {
    override var body: AnyView {
        var contentView = ContentView()
        contentView.environmentObject(DataModel())
        contentView.delegate = self
        let contentWrapperView = AnyView(contentView)
        return contentWrapperView
    }
}

Answer 3

For anyone like Brett (in the comments) who was getting

"Property 'body' with type 'AnyView' cannot override a property with type 'ContentView'"

I got the same error because I hadn't replaced the return value and wrapped the ContentView being returned.

ie. this is what my first attempt looked like.. notice the WKHostingController<ContentView> that should be WKHostingController<AnyView>

class HostingController : WKHostingController<ContentView> {
    override var body: AnyView {
        return AnyView(ContentView().environmentObject(DataModel()))
    }
}