This is what I used to do:
UIWebView * webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 0, 0)];
NSString *urlString = @"https://itunes.apple.com/us/app/watuu/id304697459";
NSString * content = [NSString stringWithFormat : @"<head><meta http-equiv='refresh' content='0; URL=%@'></head>", urlString];
[webView loadHTMLString:content baseURL:nil];
[self.view addSubview:webView];
[webView performSelector:@selector(removeFromSuperview) withObject:nil afterDelay:2.0];
Please note that in this case I am instantiating this call from the UIInputViewController.
This method should also work using the URL scheme from the containing app
UPDATE 04/17/2015: This does not work with iOS 8.3. We are looking for a solution and we will update the answer soon
UPDATE 06/01/2015: We found a solution that works in iOS 8.3
var responder = self as UIResponder?
while (responder != nil){
if responder!.respondsToSelector(Selector("openURL:")) == true{
responder!.callSelector(Selector("openURL:"), object: url, delay: 0)
}
responder = responder!.nextResponder()
}
This will find a suitable responder to send the openURL to.
You need to add this extension that replaces the performSelector for swift and helps in the construction of the mechanism:
extension NSObject {
func callSelector(selector: Selector, object: AnyObject?, delay: NSTimeInterval) {
let delay = delay * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue(), {
NSThread.detachNewThreadSelector(selector, toTarget:self, withObject: object)
})
}
}
UPDATE 06/15/2015: Objective-C
Someone asked for the code in Objective-C so here it is. I am not going to run it as I don't have the time right now but it should be quite straightforward:
UIResponder *responder = self;
while(responder){
if ([responder respondsToSelector: @selector(OpenURL:)]){
[responder performSelector: @selector(OpenURL:) withObject: [NSURL URLWithString:@"www.google.com" ]];
}
responder = [responder nextResponder];
}
As mentioned, I have not run this Objective-C code, it is just a conversion from the Swift code. Please let me know if you encounter any issues and the solution and I will update it. Nowadays, I am just using swift and unfortunately my brain is deprecating Objective-C
UPDATE 05/02/2016: Deprecated functions
As pointed by @KyleKIM the Selector functions have been replaced in Swift 2.2 by #selector. Also, there is a function that is deprecated and will probably get removed in Swift 3.0 so I am doing some research to find an alternative.
UPDATE 09/16/2016: XCode 8, Swift 3.0 and iOS10
The following code is still working on the mentioned versions. You will get some warnings:
let url = NSURL(string:urlString)
let context = NSExtensionContext()
context.open(url! as URL, completionHandler: nil)
var responder = self as UIResponder?
while (responder != nil){
if responder?.responds(to: Selector("openURL:")) == true{
responder?.perform(Selector("openURL:"), with: url)
}
responder = responder!.next
}
UPDATE 6/15/2017: XCode 8.3.3
let url = NSURL(string: urlString)
let selectorOpenURL = sel_registerName("openURL:")
let context = NSExtensionContext()
context.open(url! as URL, completionHandler: nil)
var responder = self as UIResponder?
while (responder != nil){
if responder?.responds(to: selectorOpenURL) == true{
responder?.perform(selectorOpenURL, with: url)
}
responder = responder!.next
}
A Today widget (and no other app extension type) can ask the system to open its containing app by calling the openURL:completionHandler: method of the NSExtensionContext class.An interesting workaround is below in the comments. – Pearly