I have four views in my storyboard
ViewOne
ViewTwo
ViewThree
ViewFour
In my ViewTwo, I make a call and open an new App and when the URL opening is done I call the following function in my Appdelegate
func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool
What I do here is that I iterate through all my viewControllers because I want to find my ViewTwo to be able to call a segue that I have created. I want to do it this way because I don´t want to create a new instance of the viewController.
It works great with this function below to find ViewTwo:
if let viewControllers = window?.rootViewController?.childViewControllers {
for viewController in viewControllers {
if viewController.isKindOfClass(ViewTwo) {
viewController.performSegueWithIdentifier("sw", sender: self)
}
}
}
But now I have added a NavigationController to ViewTwo, ViewThree and ViewFour so when I run the snippet above I only get the following result for viewController (I made a simple print(viewController))
<ViewOne: 0x...>
<UINavigationController: 0x...>
<UINavigationController: 0x...>
<UINavigationController: 0x...>
So my question is, how do I check for ViewTwo now that I also have a NavigationController?
I solved this by
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewControllerWithIdentifier("ViewThree") as! WebViewController
self.window?.rootViewController!.presentViewController(controller, animated: true, completion: { () -> Void in
})
You can get the view controller from storyboard without creating a new instance. You don't need to iterate through all the view controllers. Also why do you not set the view controller as the root of your nav controller instead of performing a segue?
You can get the view controller from storyboard like this:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewControllerWithIdentifier("ViewTwo") as! ViewTwoViewController
Because now you are all getting UINavigationViewController. And it's just simply a controller of controller. You can access the root view controller from UINavigationViewController by accessing the first element of viewControllers property. Then, you are able to make the interpolation.
The root view controller is at index 0 in the array, the back view
controller is at index n-2, and the top controller is at index n-1,
where n is the number of items in the array.
Related
Im trying to open a certain view from a push notification but i keep losing the nav bar and the back and next references. this what my storyboard looks like this (with the view i want to open)
this is what i have in my AppDelagate:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "notification") as? NotificationViewController
self.window?.rootViewController = vc
What you're doing is completely replacing the root view controller of your application, this means that all the current UI will be discarded.
What you should do instead is to use your knowledge of your application to direct it to the new content. For example, if your root view controller is a navigation controller, you can cast rootViewController to a nav controller and push it (this will fail if your root view controller is something else, like a tab bar controller).
guard let vc = storyboard.instantiateViewController(withIdentifier: "notification") as? NotificationViewController else {
fatalError("Main Storyboard doesn't have a notification controller")
}
guard let nav = self.window?.rootViewController as? UINavigationController else {
return //handle unexpected state
}
nav.push(vc, animated: true)
Another option would be to embed your notification controller into a navigation controller, add a Close button, and present it modally, that way you can present it on top of rootViewController no matter what that controller is.
As we can see in the screenshot your provided, the application's root view controller is the UINavigationController instance.
And according to that, let me offer the next code:
func handleNotification(){
let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let vc = storyboard.instantiateViewController(withIdentifier: "notification") as? NotificationViewController else{
debugPrint("NotificationViewController with identifier 'notification' not found")
return
}
guard let navVC = self.window?.rootViewController as? UINavigationController else{
debugPrint("RootViewController is not an UINavigationController")
return
}
navVC.pushViewController(vc, animated: true) //perhaps your will prefer to use false
}
Beside that, you can use more flexible implementation.
In your AppDelegate post a (NS)Notification when notification intercepted, the relevant view-controller(s) observe the notification, and act when notification broadcasted.
You can also set an identifier to the segue and invoke performSegue method from the observing view-controller
You can set from storyboard -> add view controller -> Embed in navigation controller -> set second view controller -> Attach seque between that controllers. You will see same view controllers like that image .
I have a background task that runs from AppDelegate, when it needs to it displays notifications.
When these notifications are tapped they should direct the user to the ViewController that relates to the notification.
I was wondering if it was possible to perform segues from AppDelagate.
My ViewControllers are in a navigation controller. I'm guessing I have to instantiate my root view controller and perform segue there, just not sure how to do that from appdelegate.
Edit:
Here is my code so far, it works it just isn't embedded in my navigation controller
if let controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ConversationVC") as? conversationTableViewController {
if let window = self.window, let rootViewController = window.rootViewController {
var currentController = rootViewController
while let presentedController = currentController.presentedViewController {
currentController = presentedController
}
currentController.present(controller, animated: true, completion: nil)
}
}
You can't segue from a storyboard that isn't loaded yet.
Depending on your case you could:
1: Send data from the AppDelegate to the initial root view controller of your current storyboard and from there, create multiple segues to the respectable VC depending on the data.
OR
2: Create multiple storyboards (one for each case) and launch the appropriate ones from the AppDelegate according to the notification.
Edit: Need to see the storyboard. For the variable, add it to conversationTableViewController and set it up just before you present it:
controller.myVar = "someValue"
self.window.rootViewController = controller
self.window.makeKeyAndVisible()
So i've implemented universal link in my app and when pressing on a button I open my second app with :
UIApplication.shared.open(aUrl!)
also I'm getting the call in :
func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: #escaping ([Any]?) -> Void) -> Bool {}
which is an alert.
The question is like the title says..how could I navigate to a specific VC ,(from the FirstApp to the Second which i opened it with universal link), more like mapping a navigation controller stack .
I've writed something like :
if let controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "MyAdsController") as? MyAdsViewController {
if let window = self.window, let rootViewController = window.rootViewController {
var currentController = rootViewController
while let presentedController = currentController.presentedViewController {
currentController = presentedController
}
currentController.present(controller, animated: true, completion: nil)
}
}
but it's an ugly representation, i need something like the hole navigation stack...
And also , can i make a helper class for this if i want to handle more with universal link? Any suggestion are appreciated.
You need to use the .viewControllers property of your UINavigationController you can do this using setViewControllers(_:animated:) method or modifying directly .viewControllers property where rootViewController will be the viewControllersArray[0] and topViewController will be viewControllersArray[count-1]
This property description and details can be founded in the UINavigationController documentation
viewControllers
Property
The view controllers currently on the navigation stack.
Declaration
SWIFT
var viewControllers: [UIViewController]
Discussion The root view controller is at index 0 in the array, the back view controller is at index n-2, and the top controller is at
index n-1, where n is the number of items in the array.
Assigning a new array of view controllers to this property is
equivalent to calling the setViewControllers:animated: method with the
animated parameter set to false.
example
let storyboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let firstViewController = storyboard.instantiateViewController(withIdentifier: "FirstViewController") as? FirstViewController
let secondViewController = storyboard.instantiateViewController(withIdentifier: "SecondViewController") as? SecondViewController
let thirdViewController = storyboard.instantiateViewController(withIdentifier: "ThirdViewController") as? ThirdViewController
self.navigationController?.setViewControllers([firstViewController,secondViewController,thirdViewController], animated: false)
Alright so this is less of a Universal Link question and more of a navigation preference. When you are passed a universal link in your continueUserActivity function you should parse it and navigate accordingly from your app delegate. You should really switch your Universal Link handling to Branch since they will handle this for you for free and they pass metadata through a callback instead of link parameters which will make your links more powerful. Anyways...
Start with a UINavigationViewController
This consists of having a rootViewController which should be an instance of your main page. Store this navigation view controller as an instance variable so your app is only dealing with one Navigation view controller on launch. If you're using a storyboard then you can just just get reference to that navigation view controller:
self.nav = self.window?.rootViewController as? UINavigationViewController
Pushing vs presenting a View Controller onto Nav
When you receive a link and determined that you need to bring that user to a new page, you should decide whether to push or present the VC.
Pushing
Pushing is necessary if you would like to maintain that view as part of a stack. For example, if you want to show the user a pair of shoes, you may want to take them into the shoes category, then present them with the shoe detail controller. In this case you could take the user to the home page and push the proper navigation stack onto your UINavigationViewController.
self.nav.popToRootViewController(animated: true)
self.nav.pushViewController(firstController, animated: true)
self.nav.pushViewController(secondViewController, animated: true)
This way your users UINavigationController stack will look like root > firstVC > secondVC and they will have bread crumbs to be able to traverse back through the flow.
Presenting
In the case that you do not want to push a view onto the stack. Maybe you want to present a popup regardless of where they are at in the app and you don't want to mess up their location, you should use present a VC. This will simply present a ViewController over the entire NavigationController without being added to the NavigationController's stack.
self.nav.presentViewController(modalVC, animated:true, completion: nil)
From within that modalVC you can call
self.dismiss(animated: true, completion: nil)
In my app I am making the account page the new root VC when a user logs in.
It looks like this:
Navigation controller -> table view -> menu(modal segue) -> login screen(modal segue) -> account page
When transitioning from login to account I am using:
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let vc = storyboard.instantiateViewControllerWithIdentifier("testVc")
let navigationController = self.view.window?.rootViewController as! UINavigationController
navigationController.setViewControllers([vc], animated: true)
This makes the account page the new root VC. But the only problem is that once is shows up both the menu and login form is still visible ontop of the screen.
So how do I clear two old VC's shown as modal?
Update got it to work using:
#IBAction func loginButtonDidTouch(sender: AnyObject) {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("testVc")
let navigationController = self.view.window?.rootViewController as! UINavigationController
self.presentingViewController!.presentingViewController!.dismissViewControllerAnimated(false) { () -> Void in
navigationController.setViewControllers([vc], animated: true)
}
}
But I dont know if this is the right way to do it?
You need to get the reference of those controllers, and then dismissing them.
Try this:
let loginScreen = self.window.rootViewController.presentedViewController
loginScreen.dismissViewControllerAnimated(false) { () -> Void in
let menuScreen = self.window.rootViewController.presentedViewController
menuScreen.dismissViewControllerAnimated(false, completion: nil)
}
When you're calling the original navigation stack and modifying it:
let navigationController = self.view.window?.rootViewController as! UINavigationController
You are setting the new view controller (#testVc) by replacing the only other view controller, "tableview", in that navigation stack.
The modally presented views are not a part of that particular navigation stack and instead are presented above the current navigation stack as new stacks (this gives you a pointer to the new Navigation Controller on top in the form of self.navigationController to push new views)
You can explicitly dismiss the two modally presented views by calling dismissViewControllerAnimated(_:completion:) on each, most likely by propagating the communication through a delegate response or through the completion handler.
I have a SplitViewController with a UITableViewController as the masterViewController and a UIViewController as the detailViewController.
When the user taps a cell, I need to push to a new UITableViewController. So I added a segue from the cell to a UITableViewController. But what happens is the UITableViewController gets added to the masterViewController's stack.
How can I push to a whole new UITableViewController from the masterViewController?
Here is a simple example how I approach such functionality (I created a new Master-Detail Application):
Storyboard:
Notice that the root VC is now a UINavigationController. Therefore AppDelegate must be changed accordingly:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let navCtr = self.window!.rootViewController as UINavigationController
let splitViewController = navCtr.visibleViewController as UISplitViewController
let navigationController = splitViewController.viewControllers[splitViewController.viewControllers.count-1] as UINavigationController
navigationController.topViewController.navigationItem.leftBarButtonItem = splitViewController.displayModeButtonItem()
splitViewController.delegate = self
return true
}
And then finally in MasterViewController add this:
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
tableView.deselectRowAtIndexPath(indexPath, animated: true)
if indexPath.row % 2 == 0 {
self.performSegueWithIdentifier("showDetail", sender: nil)
} else {
let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate
if let let rootCtr = appDelegate.window?.rootViewController {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let newSplit = storyboard.instantiateViewControllerWithIdentifier("SplitVC") as UISplitViewController
/// Because of Apple's "Split View Controllers cannot be pushed to a Navigation Controller"
let yetAnotherNavCtr = UINavigationController(rootViewController: newSplit)
rootCtr.presentViewController(newSplit, animated: true, completion: nil)
}
}
}
Important notes:
If you create new MasterDetail Application from the template, you have to disconnect the showDetail segue, because it is directly linked to the cell's selected callback. If you want to preserve that functionality as well, simply connect it again not from the cell itself, but from the whole VC. To be able to use it as in my funky didSelect... method that performs the showDetail segue on even rows.
The Split View presentation will work only once - I haven't implemented the whole rootViewController replacement - the lldb will complain saying: Attempt to present UISplitViewController on UINavigationController whose view is not in the window hierarchy! if you'll try to do it for the second time. But that's really up to your requirements for how you want the app to behave.
Name the SplitView Controller in Storyboard "SplitVC" (Storyboard ID) if you want to present the Split View Controller like I am doing in my code.
I got it! First I should mention Michal's answer helped me to get an idea and point me in the right direction so thanks to him.
What I did was simple actually. Before I had a View Controller with a container view embedding the split view controller. I simply went ahead and embedded that view controller in a navigation controller.
Then I added the view controller I want to segue to in the storyboard but no segue attached to it. I'm doing it programatically in the masterViewController's didSelectRowAtIndexPath method.
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
if let rootVC = appDelegate.window?.rootViewController {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let mapVC = storyboard.instantiateViewControllerWithIdentifier("MapVC") as! UIViewController
rootVC.showViewController(mapVC, sender: nil)
}
I get a reference to the rootViewController which is a navigation controller through the AppDelegate and I push the new view controller I want to it's stack.
That's it! Here's a demo project in case anyone's interested.