alert(confirm('ok?')) can't work fine in WKWebview - wkwebview

Question

error:
Warning: Attempt to present on which is already presenting
it seems the alert(confirm('ok?')); style code trigger presenting a view controller simultaneously in WKWebview's delegate, is there any way to support this?
my html:
<button onclick="alert(1);">alert</button><br>
<button onclick="alert(confirm('ok?'));">confirm</button><br>
<button onclick="alert(prompt('please input'));">text</button><br>
my code:
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler{
NSLog(#"runJavaScriptAlertPanelWithMessage:%#", message);
UIAlertController *alert = [UIAlertController alertControllerWithTitle:#"TITLE" message:message preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action = [UIAlertAction actionWithTitle:#"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
NSLog(#"runJavaScriptAlertPanelWithMessage:%#, did clicked", message);
}];
[alert addAction:action];
completionHandler();
[self presentViewController:alert animated:YES completion:nil];
}
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler{
NSLog(#"runJavaScriptAlertPanelWithMessage:%#", message);
UIAlertController *alert = [UIAlertController alertControllerWithTitle:#"TITLE" message:message preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action = [UIAlertAction actionWithTitle:#"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
NSLog(#"runJavaScriptConfirmPanelWithMessage:%#, did clicked yes", message);
}];
UIAlertAction *actionCancel = [UIAlertAction actionWithTitle:#"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
NSLog(#"runJavaScriptConfirmPanelWithMessage:%#, did click cancel", message);
}];
[alert addAction:action];
[alert addAction:actionCancel];
completionHandler(YES);
[self presentViewController:alert animated:YES completion:nil];
}

Answer 1

sorry, my bad.
you should use completionHandler in every action callback, not just put it in delegate body, so it could be this:
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler{
NSLog(#"runJavaScriptAlertPanelWithMessage:%#", message);
UIAlertController *alert = [UIAlertController alertControllerWithTitle:#"提示" message:message preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action = [UIAlertAction actionWithTitle:#"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
NSLog(#"runJavaScriptConfirmPanelWithMessage:%#, did clicked", message);
completionHandler(YES);
}];
UIAlertAction *actionCancel = [UIAlertAction actionWithTitle:#"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
NSLog(#"runJavaScriptConfirmPanelWithMessage:%#, did click cancel", message);
completionHandler(NO);
}];
[alert addAction:action];
[alert addAction:actionCancel];
[self presentViewController:alert animated:YES completion:nil];
}