How to determine iFrame finished loading in UIWebView

Question

In my app, I need a way to tell when my webview is finished loading. It is very easy to do that if content is html. However, my content source is javascript with iFrame inside,

Answer 1

(If it is the same domain) you can call a function (in the parent) from the iframe.

top.iFrameLoaded();

Answer 2

The only foolproof method I've found is to listen to the three methods that say it's about to start loading, and that it finished loading (plus equivalent for "failed"), and to manually maintain a count for each.

i.e. something like:

int outstandingRequests;

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    outstandingRequests++;
}

- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    outstandingRequests--;

    if( outstandingRequests < 1 )
    viewLoadingPleaseWait.hidden = TRUE;
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
    outstandingRequests--;
}

I've also usually had to overrid the didFail method - Apple incorrectly uses this to report that e.g. the YouTube player has taken over the handling of a YouTube video. It's NOT a fail, it's a "page was loaded by a different application".

e.g.

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
    outstandingRequests--;

    if( [error code] == NSURLErrorCancelled )
    {
        NSLog(@"[%@] ...webView CANCELLED loading", [self class] );
    }
    else if( [[error domain] isEqualToString:@"WebKitErrorDomain"]
    && [error code] == 204)
    {
        // no worries ... YouTube, iCal, or etc took over the page load
    }
}

Answer 3

To tell if a webview is loading, you can use webView.isLoading to check if all the frames of a webview are done loading. No counting the number of iframes necessary. Simply check if isLoading is true inside webViewDidFinishLoad:

http://developer.apple.com/library/ios/#documentation/uikit/reference/UIWebView_Class/Reference/Reference.html