[iOS, Objective-c] WKWebView Custom User-Agent

wkwebviewUserAgent.m

- (void)setupCustomUserAgent
{
    [self.webView evaluateJavaScript:@"navigator.userAgent" completionHandler:^(NSString *aUserAgent, NSError *aError) {
        
        NSString *sCustomUserAgent = @"additional custom user-agent";
        
        if (aUserAgent.length > 0 && aError == nil) {
            
            sCustomUserAgent = [NSString stringWithFormat:@"%@ %@", aUserAgent, sCustomUserAgent];
        }
        
        self.webView.customUserAgent = sCustomUserAgent;
    }];
}