Detect and Customize UIWebView's "Unable to Read Document" error

Question

I'm testing a UIWebview with a number of different document types - .xlsx, .jpg, etc. - and it opens most of them just fine. From time to time, I open a local file and this message appears right in the web view:

Unable to Read Document
An error occurred while reading the document

I'm not concerned with "why" this error occurs - it happens, for instance, when I feed the UIWebView a garbage file (intentionally). The problem is that I can't figure out how to detect "when" this happens. It doesn't trigger webView:didFailLoadWithError, it doesn't trigger an NSException (via @try & @catch), and when I inspect the document in webViewDidFinishLoad, webView.request.HTTPBody is null.

Anyone know how to detect when UIWebView can't display content?

Answer 1

just call uiwebview delegate method 

- (void)webViewDidStartLoad:(UIWebView *)webView
{

}
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    NSString *html = [webView stringByEvaluatingJavaScriptFromString:
                      @"document.body.innerHTML"];
    if ([html rangeOfString:@"Unable to Read Document."].location == NSNotFound) {

       NSLog(@"NO Error");

    }
    else
    {
//        NSLog(@"File contains Error");
    }

}