How to submit a form in WKWebView Swift? - ios

Question

I've been trying to use WKWebView to fill in a webform and submit. So far I have been able to do that. The problem is the WebView form loop endlessly from "insert element, "trying to submit" to "submited" once I used the below code.
let submitFunction = document.forms[0].submit();
Anyone knows what is happening? How can I rewrite this code?
Thank you very much!
import UIKit
import WebKit
class AnswerVC: UIViewController {
#IBOutlet weak var webView: WKWebView!
var questionText = "1+1"
override func viewDidLoad() {
super.viewDidLoad()
webView.navigationDelegate = self
}
override func viewWillAppear(_ animated: Bool) {
let url:URL = URL(string: "https://gamma.sympy.org/")!
let urlRequest:URLRequest = URLRequest(url: url)
webView.load(urlRequest)
}
}
extension AnswerVC: WKNavigationDelegate {
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
print("insert element")
let scriptFunction = "document.getElementById('id_i').value = '\(questionText)';"
webView.evaluateJavaScript(scriptFunction) { (result, error) in
if error != nil {
ProgressHUD.showError(error as? String)
} else {
print("trying to submit")
let submitFunction = "document.forms[0].submit();"
webView.evaluateJavaScript(submitFunction) { (result, error) in
if error != nil {
print(error?.localizedDescription)
} else {
print("submited")
}
}
}
}
}
}