UIWebView open links in Safari

Add this to the UIWebView delegate:

(edited to check for navigation type. you could also pass through file:// requests which would be relative links)

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    if (navigationType == UIWebViewNavigationTypeLinkClicked ) {
        [[UIApplication sharedApplication] openURL:[request URL]];
        return NO;
    }

    return YES;
}

Swift Version:

func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {
        if navigationType == UIWebViewNavigationType.LinkClicked {
            UIApplication.sharedApplication().openURL(request.URL!)
            return false
        }
        return true
    }

Swift 3 version:

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
    if navigationType == UIWebViewNavigationType.linkClicked {
        UIApplication.shared.openURL(request.url!)
        return false
    }
    return true
}

Swift 4 version:

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebView.NavigationType) -> Bool {
    guard let url = request.url, navigationType == .linkClicked else { return true }
    UIApplication.shared.open(url, options: [:], completionHandler: nil)
    return false
}

Update

As openURL has been deprecated in iOS 10:

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
        if (navigationType == UIWebViewNavigationTypeLinkClicked ) {
            UIApplication *application = [UIApplication sharedApplication];
            [application openURL:[request URL] options:@{} completionHandler:nil];
            return NO;
        }

        return YES;
}

If anyone wonders, Drawnonward's solution would look like this in Swift:

func webView(webView: UIWebView!, shouldStartLoadWithRequest request: NSURLRequest!, navigationType: UIWebViewNavigationType) -> Bool {
    if navigationType == UIWebViewNavigationType.LinkClicked {
        UIApplication.sharedApplication().openURL(request.URL)
        return false
    }
    return true
}

One quick comment to user306253's answer: caution with this, when you try to load something in the UIWebView yourself (i.e. even from the code), this method will prevent it to happened.

What you can do to prevent this (thanks Wade) is:

if (inType == UIWebViewNavigationTypeLinkClicked) {
    [[UIApplication sharedApplication] openURL:[inRequest URL]];
    return NO;
}

return YES;

You might also want to handle the UIWebViewNavigationTypeFormSubmitted and UIWebViewNavigationTypeFormResubmitted types.