How do I fix NSURLErrorDomain error -999 in iPhone 3.0 OS

Question

I am trying to update my iPhone app to work with OS 3.0. I have a UIWebView that shows a page fine. But when I click a link it calls my delegate for didFailLoadWithError and the error is Operation could not be completed. (NSURLErrorDomain error -999.) I verified this is still working with OS 2.2.1, so it is something changed in 3.0.

Any ideas?

Varick

details like which page are in the UIWebView (if it's public) and how you setup this view and delegate in code might be useful. – Piero

I am on the road now and will get more details added when I get back. It is a public web page. In further digging it looks like it may be related to a page not being fully loaded before the next request is received. I have not had a chance to test that yet. If that proves to be the issue I will update. – Varick

I think you need to revisit which is considered the correct answer – Cumulous

Answer 1

I was able to find the answer here.

This thread contained this description for this error: This error may occur if an another request is made before the previous request of WebView is completed...

I worked around this by ignoring this error and letting the webview continue to load.

if ([error code] != NSURLErrorCancelled) {
//show error alert, etc.
}

Varick

Better to use the constant NSURLErrorCancelled instead of the literal value -999. – Hexa

This error may also be a code smell. I got rid of it not by ignoring it, but by moving a load-triggering method call from viewDidAppear (which could trigger multiple times while loading the web view) into viewDidLoad. – Prokofiev

Better yet, the uiwebview has a boolean "loading" property that you should check and then explicitly stop the loading operation. However, in my case this seems to be the result of deallocating the webview. – Cherisecherish

I got rid of it by forcing to reload the url a few times by putting the request in the delegate method - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error. This helps for Twitter and Facebook annoyances – Bluet

Man, I owe you a beer – Rachelrachele

Answer 2

NSURLErrorCancelled (-999)

"Returned when an asynchronous load is canceled. A Web Kit framework delegate will receive this error when it performs a cancel operation on a loading resource. Note that an NSURLConnection or NSURLDownload delegate will not receive this error if the download is canceled."

For my situation (and probably yours) this can be ignored:

if([error code] == NSURLErrorCancelled) return; // Ignore this error

Friedlander

Answer 3

The above TWO replies was CORRECT> Just do a return if the loading request causes cancellation.

Also I want to point out that, people do NOT forget to put an NSLog inside your didFailLoadWithError method, this can prevent losing a lot of time by spotting the issue right on!

So here is the final solution with all I mentioned above:

-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
    NSLog(@"ERROR : %@",error); //Get informed of the error FIRST
    if([error code] == NSURLErrorCancelled) 
        return;
}

Rhodolite