WKWebView doesn't show from the begin in NSViewRepresentable

The problem is that WKWebView can't do anything until the view is properly loaded and initialized. You might want to move the "load..." call into a Dispatch.async... call. That way it'll be called after the web view has been returned (and hopefully has been initialized).

Here is a quick playground example.

import SwiftUI
import WebKit
import PlaygroundSupport

struct WebView: UIViewRepresentable {
    func makeUIView(context: UIViewRepresentableContext<WebView>) -> WKWebView {
        let view = WKWebView()
        DispatchQueue.main.async {
            let url = URL(string:"https://example.com")!
            let request = URLRequest(url: url)
            view.load(request)
        }
        return view
    }

    func updateUIView(_ uiView: WKWebView, context: UIViewRepresentableContext<WebView>) {
        //
    }

    typealias UIViewType = WKWebView
  }  


struct ContentView : View {
    var body: some View {
        WebView()
    }
}


// Present the view controller in the Live View window
PlaygroundPage.current.liveView = UIHostingController(rootView: ContentView())

Moving the load() call into updateNSView() appears to do the trick, though since that method is called on every single event (including mouse-over events), you need to be able to exit quickly after the first time you load the URL.

Here's my implementation:

import SwiftUI
import WebKit

struct WebView: NSViewRepresentable {
    let url: URL

    func makeNSView(context: Context) -> WKWebView {
        let view = WKWebView()
        view.autoresizingMask = [.width, .height]
        return view
    }

    func updateNSView(_ nsView: WKWebView, context: Context) {
        guard context.coordinator.needsToLoadURL else { return }
        nsView.load(URLRequest(url: url))
    }

    func makeCoordinator() -> WebView.Coordinator {
        Coordinator()
    }

    class Coordinator {
        var needsToLoadURL = true
    }
}

struct WebKitView_Previews: PreviewProvider {
    static var previews: some View {
        WebView(url: URL(string: "...")!)
    }
}