Xcode, Swift; Detect hyperlink click in UIWebView

I made an iOS app with Xcode and Swift.

I want to open specific hyperlinks in Safari browser, there others in the WebView itself.

To reach this, I'll have to check when an hyperlinks gets clicked.

This is the code I have so far:

//
//  PushViewController.swift
//  App
//
//

import UIKit
class PushViewController: UIViewController, UIWebViewDelegate {
    @IBOutlet var openpushmessage: UIWebView!

    var weburl:String = "http://www.example.com"

    override func viewDidLoad() {
        super.viewDidLoad()

        let url: NSURL = NSURL(string: weburl)!
        let requestURL: NSURLRequest = NSURLRequest(URL: url)
        openpushmessage.loadRequest(requestURL)
    }
    override func webView(_ webView: UIWebView, shouldStartLoadWithRequest request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
        if navigationType == .linkClicked
        {
            print("You clicked a hypelink!")
        }
        return true
    }
}

The code in viewDidLoad() opens the loads the main URL (http://www.example.com) from my server. That works fine.

override fun webView[…] should detect if a hyperlink is clicked and then print("You clicked a hypelink!").

But unfortunately I'm getting the following errors:

What am I doing wrong? How to get rid of these errors?

This is the working solution (Xcode 7.3.1 and Swift 2.2):

func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {

    if request.URL?.query?.rangeOfString("target=external") != nil {
        if let url = request.URL {
            UIApplication.sharedApplication().openURL(url)
            return false
        }
    }
    return true
}

Many thanks to danhhgl from freelancer.com!