Check if an URL has got http:// prefix

Question

In my application, when the user add an object, can also add a link for this object and then the link can be opened in a webView.
I tried to save a link without http://

Answer 1

NSString * urlString = ...;
NSURL * url = [NSURL URLWithString:urlString];
if (![[url scheme] length])
{
  url = [NSURL URLWithString:[@"http://" stringByAppendingString:urlString]];
}