Send data from Javascript to iOS code

Configure a WKUserContentController on the WKWebView to receive data

class MessageHandlerLeakAvoider: NSObject, WKScriptMessageHandler {
    weak var delegate: WKScriptMessageHandler?
    
    init(delegate: WKScriptMessageHandler) {
        self.delegate = delegate
        super.init()
    }
    
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
            self.delegate?.userContentController(
                userContentController, didReceive: message)
    }
}

let contentController = webView.configuration.userContentController
contentController.add(MessageHandlerLeakAvoider(self), name: "messageHandler")

extension ArticleViewController: WKScriptMessageHandler{
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
       	guard let dict = message.body as? [String : AnyObject] else {
            return
        }

        print(dict)
    }
}

Send the data from Javascript

if (window.webkit && window.webkit.messageHandlers && window.webkit.messageHandlers.messageHandler) {
    window.webkit.messageHandlers.messageHandler.postMessage({
        "message": ""
    });
}

Send data from iOS to Javascript code

Execute Javascript code on the webview to pass data to the web context.

let script = "window.updateFromNative(" + eventValue + ")"
webView.evaluateJavaScript(script) { (result, error) in
	if let error {
		print(error)
	}
}

Create a Javascript method updateFromNative to receive the data passed

window.updateFromNative = function (nativeData) {

};

Implement Engagement Starter

Show a Engagement Starter inside the WebView content and link it with the SDK.

func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
  self.webView.evaluateJavaScript(
    """
     setTimeout(function() {
                            document.querySelector('.vf-conversation-starter_link').onclick = function() {
                               if (window.webkit && window.webkit.messageHandlers && window.webkit.messageHandlers.messageHandler) {
                                    window.webkit.messageHandlers.messageHandler.postMessage({
                                        "action": "ENGAGEMENT_STARTER_CLICKED"
                                    });
                                }
                            };
    }, 2000);
    """)
}

extension ArticleViewController: WKScriptMessageHandler{
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        guard let data = message.body as? [String : AnyObject] else {
            return
        }
        
        if data["action"] as? String == "ENGAGEMENT_STARTER_CLICKED" {
            let originY = scrollView.convert(CGPoint.zero, from: commentsContainerView).y
            scrollView.setContentOffset(CGPoint(x: 0, y: originY), animated: true)
        }
    }
}