target="_blank" on href elements has no effect

[lgrimes]

Description
We have standard href link which is meant to take the user out of the app and to http://facebook.com/shared/sharer.php.

<a class="Share-link m-facebook" href="http://www.facebook.com/sharer/sharer.php?u=ourdomain&amp;title=blah blah" target="_blank"></a>

As we are using the same on our web app, we want the link to take the user to a new window, rather than reloading the current one (hence target="_blank"). This is working completely fine. With this on the tag, the iOS app receives no callback of any kind that a link has been clicked. Nothing from the WKWebView delegate methods is triggered. openExternalURL in the Session is never called.

If however, we remove target="_blank" then the link will open in an external safari window as expected. Our work around has been to pass a flag when the page is loaded from a native webview that will not apply the target tag to the element.

Is this expected functionality?

[huacnlee]

I have same issue.

[zachwaugh]

@lgrimes @huacnlee any links with target=_blank should hit the WKNavigationDelegate where they can be handled. By default, the Turbolinks.Session will set itself as the WKNavigationDelegate and handle any link clicks for the main frame and open them externally. It sounds like either you are implementing sessionDidLoadWebview() which will cause the default navigation delegate not to be set, or the link click isn't occurring in the main frame.

As a test, I'd try setting your own code to be the WKNavigationDelegate for the web view and implement func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> ()) and logging to ensure that delegate method is being hit.

[huacnlee]

My case:

extension TurbolinksSessionLib: SessionDelegate {
    func sessionDidLoadWebView(session: Session) {
        // [breakpoint] looks like there may have no call 
        session.webView.navigationDelegate = self
    }
}

extension TurbolinksSessionLib: WKNavigationDelegate {
    func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> ()) {
        let url = navigationAction.request.URL
        if (url?.host != NSURL(string: ROOT_URL)?.host) {
            let safariViewController = SFSafariViewController(URL: url!)
            topNavigationController?.presentViewController(safariViewController, animated: true, completion: nil)
        } else {
            actionToPath((url?.path)!, withAction: .Advance)
        }
        decisionHandler(.Cancel)
    }
}

I had try to add breakpoint on sessionDidLoadWebView, but in sometimes, it does't hit.

[lgrimes]

In extension of SessionDelegate, i am only overriding didProposeVisitToURL, didFailRequestForVisitable and sessionDidFinishRequest. So I'm not extending sessionDidLoadWebview at all.

Im setting the session in my ViewController like such:

  private final let webViewProcessPool = WKProcessPool()

  lazy final var webViewConfiguration: WKWebViewConfiguration = {
    let contentController = WKUserContentController.init()
    let configuration = WKWebViewConfiguration()
    configuration.userContentController = contentController
    configuration.processPool = self.webViewProcessPool
    return configuration
  }()

  lazy var session: Session = {
    let session = Session(webViewConfiguration: self.webViewConfiguration)
    return session
  }()

  override func viewDidLoad() {
    super.viewDidLoad()
    session.delegate = self
    presentVisitableForSession(session, URL: url, action: .Replace)
  }

Ive also set some breakpoints in decidePolicyForNavigationAction and when clicking anything with target="_blank" this is not being called. However all other links, redirects and page loads work fine. If i remove this, it opens into a new window (external safari) as you would expect.

[jdiepenmaat]

Same issue here.

[dinomite]

Any new ideas here? I've got a very simple application with a SessionDelegate overriding the minimum just as @lgrimes described, with the addition of openExternalURL, as I'd like to open external URLs in a SFSafariViewController as described in the README. I too am finding that that overridden method isn't being called and, indeed the decidePolicyForNavigationAction doesn't seem to get called either if I set my own NavigationDelegate.

[dinomite]

Update! Fixed it thanks to finding this question about how to handle target=_blank. I created a UIDelegate:

extension AppController: WKUIDelegate {
    func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
        if navigationAction.targetFrame == nil {
            webView.load(navigationAction.request)
        }

        return nil
    }
}

And assigned it to the Session's WKWebView:

    let session = Session(webViewConfiguration: self.webViewConfiguration)
    session.delegate = self
    session.webView.uiDelegate = self

[chamnap]

I'm having the same issue. I already tried out on the demo application, and it has the same problem. Removing target=blank, it will open in an external safari window.

[chamnap]

@zachwaugh, I check out the code. This method, #isMainFrameNavigation, https://github.com/turbolinks/turbolinks-ios/blob/master/Turbolinks/Session.swift#L309 returns false, where navigationAction.targetFrame is nil.

From the apple documentation, https://developer.apple.com/reference/webkit/wknavigationaction/1401918-targetframe, it returns nil because it is new window navigation.

[zachwaugh]

Thanks for digging in @chamnap! That was the issue, our default check was too restrictive. I just pushed a change that opens all links that Turbolinks doesn't handle directly to open in Safari. That should make the WKUIDelegate implementation above unnecessary.

My apologies for not fixing this sooner, I was testing in our app, which had custom handling in place for the WKNavigationDelegate and target=_blank links worked correctly there. The demo app uses the default navigation delegate handler where target blank links did not work.