Actions within webview - iOS

Question

good afternoon! Can anyone help me? I’m starting iOS development and I have a problem. A website on which I am creating a webview (with Mkwebview) sends alerts to the user when doing some action but in the webview I cannot make this notification appear. What can be happening? Who can help me I thank.

  import UIKit class ViewController: UIViewController, UIWebViewDelegate 
{ 
var webView: UIWebView! override func viewDidLoad()
 {
 super.viewDidLoad() webView = UIWebView(frame: UIScreen.main.bounds) webView.delegate = self view.addSubview(webView) if let url = URL(string: "office.unick.forex/login.php") 
{
 let request = URLRequest(url: url) webView.loadRequest(request) 
} 
}
 }

Answer 1

Analyzing your code I found that:

• No communication between client (web page) and container (iOS).
• The Uiwebview component was depreciated consequently, use the Wkwebview.

Thus, to display the alert correctly, your code should have a structure close to the example below:

import UIKit
import WebKit

class ViewController: UIViewController, WKUIDelegate, WKScriptMessageHandler {

    // Troquei de UIWebView para WKWebView
    var webView: WKWebView!

    override func viewDidLoad() {
        webView = WKWebView(frame: UIScreen.main.bounds)

        webView.configuration.userContentController.add(self, name: "alerta") //window.webkit.messageHandlers.alerta.postMessage("trigger from JS");
        webView.uiDelegate = self
        self.view.addSubview(webView)

        if let url = URL(string: "http://office.unick.forex/login.php")
        {
            let request = URLRequest(url: url)
            webView.load(request)
        }
    }

    func alertaGenerico() {
        let alertController = GlobalAlertController(title: "", message: "Você tem certeza?", preferredStyle: .alert)

        let cancelar = UIAlertAction(title: "Cancelar", style: .default, handler: nil)
        alertController.addAction(cancelar)

        let ok = UIAlertAction(title: "Ok", style: .default, handler: nil)
        alertController.addAction(ok)

        alertController.show()
    }

    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == "alerta" {
            print(message.body)
            alertaGenerico()
        }
    }
}

//--------
// MARK: - Exibição global na UIViewController
//--------
protocol GlobalWindow {
    func show(animated flag: Bool, completion: (() -> Void)? )
}

extension GlobalWindow where Self : UIViewController {

    func show(animated flag: Bool = true, completion: (() -> Void)? = nil) {
        if let window = UIApplication.shared.keyWindow?.rootViewController {
            window.present(self, animated: flag, completion: completion)
        }
    }
}

class GlobalAlertController : UIAlertController, GlobalWindow {}

To test the above code, run the javascript command on the console or directly on some site function:

window.webkit.messageHandlers.alerta.postMessage("texto de parametro");

Evidence of testing:

Don’t forget to add the information NSAppTransportSecurity in your plist file, otherwise your site might not be loaded.