Create WKWebView_logging.md

IOS/WKWebView_logging.md

@@ -0,0 +1,48 @@
+```swift
+import SwiftUI
+import WebKit
+import JavaScriptCore
+
+struct ContentView: View {
+    var body: some View {
+        WebView()
+    }
+}
+
+#Preview {
+    ContentView()
+}
+
+struct WebView: UIViewRepresentable {
+ 
+    let webView: WKWebView
+    
+    init() {
+        webView = WKWebView(frame: .zero)
+      
+    }
+    
+    func makeUIView(context: Context) -> WKWebView {
+        let source = "function captureLog(msg) { window.webkit.messageHandlers.logHandler.postMessage(msg); } window.console.log = captureLog;"
+        let script = WKUserScript(source: source, injectionTime: .atDocumentEnd, forMainFrameOnly: false)
+        webView.configuration.userContentController.addUserScript(script)
+        // register the bridge script that listens for the output
+        webView.configuration.userContentController.add(Controller(), name: "logHandler")
+        
+        return webView
+    }
+    func updateUIView(_ uiView: WKWebView, context: Context) {
+        webView.load(URLRequest(url: URL(string: "http://localhost:8000/demo")!))
+    }
+}
+
+
+class Controller: NSObject, WKScriptMessageHandler{
+    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
+        if message.name == "logHandler" {
+            print("LOG: \(message.body)")
+        }
+    }
+}
+
+```