iOS webpage doesn't load unless button is tapped twice - iphone

Question

- (IBAction)saveButton:(id)sender
{
NSURL *yourURL = [NSURL URLWithString: webpageURLLabel.text ];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:yourURL];
if ([self checkURL] == YES) {
[webpagePreview loadRequest:request];
webpagePreview.scalesPageToFit = YES;
}
}
- (BOOL)checkURL
{
NSString *arrayOfStrings = [NSArray arrayWithObjects:#"http://", #"https://", nil];
NSString *stringToSearchWithin = webpageURLLabel.text;
BOOL found=NO;
for (NSString *s in arrayOfStrings)
{
if ([stringToSearchWithin rangeOfString:s].location != NSNotFound)
{
found = YES;
break;
} else
{
webpageURLLabel.text = [NSString stringWithFormat:#"http://%#", webpageURLLabel.text];
found = YES;
break;
}
}
return found;
}
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
webpageTitleLabel.text = [webpagePreview stringByEvaluatingJavaScriptFromString:#"document.title"];
}
I debugged it and it looks like it is suppose to load. But for some reason, when you tap the button the first time, nothing happens.
If the user taps the button a second time, it works fine. Any suggestions?

Answer 1

Looks to me like the first time the button is clicked, webpageURLLabel.text may not have a valid URL, and so the request is not valid. Then when [self checkURL] is called, webpageURLLabel.text gets set to a valid URL, and so the next click works.
Maybe you should be calling -checkURL before you create the NSURLRequest?

Answer 2

There are also problems in checkURL. Note that it always returns YES. Inside the for loop is logic that reduces to:
if (some condition) {
found = YES;
break;
} else {
// Fix webpageURLLabel.text
found = YES;
break;
}
However, consider what happens if you have a valid entry that starts with #"https://". The first time through the loop the if condition fails and so #"http://" gets added to the front of the URL and you return. So #"https://valid.com" turns into #"http://https://valid.com". You need to move everything in the else outside the for loop and do it only if found is not true.