Swift Navigating to ViewController thats 3 windows deep - ios

I have a ViewController that I want to present when a push notification is opened from the locked screen.
The view controller is embedded inside a chain of view controllers, the chain is:
TabbedBarController(root) -> NavigationController0 -> ViewController0 -> ViewController1 -> ViewControllerIWant
I have two variables from the push notification I want to pass into ViewControllerIWant
So far I have:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let rootVC = storyboard.instantiateViewControllerWithIdentifier("HomeVC") as! UITabBarController // HomeVC is the TabbedBarController
let NaviVC = storyboard.instantiateViewControllerWithIdentifier("NavigationController0") as! UINavigationController // NavigationController0 is the Navigation Controller for this stack
let ViewController0 = storyBoard.instantiateViewControllerWithIdentifier("ViewController0") as ViewController0
let ViewController1 = storyBoard.instantiateViewControllerWithIdentifier("ViewController1") as ViewController1
let ViewControllerIWant = storyBoard.instantiateViewControllerWithIdentifier("ViewControllerIWant") as ViewControllerIWant
// Pass the Variables into ViewControllerIWant
ViewControllerIWant.Variable0 = "This is the first Variable"
ViewControllerIWant.Variable1 = "this is the second variable"
// Load the VC
self.presentViewController(ViewControllerIWant, animated:true, completion:nil)
I can load ViewControllerIWant directly but then loose the navigation and tab controllers so moving backwards requires you yo close the app and reload.
How do I nest the VC's so that when the user swipes this notification it loads ViewControllerIWant ?

You can just set the viewControllers of the navigationController. And show the current navigationController.
In your example you should add this after the line will be (I have change all to a lowercase. You really shouldn't be using a uppercase as variable)
viewControllerIWant.variable1 = "this is the second variable"
naviVC.viewControllers = [viewController0, viewController1, viewControllerIWant]

You can keep your navigation controller by using segues instead of presenting the View Controller
Once the segue is created from your starting VC into your desired VC, you give it an identifier (e.g. "segueFromVC1ToVCIWant").
Then call the method as an action of your notification:
self.performSegueWithIdentifier("segueFromVC1ToVCIWant", sender: nil)
Finally can pass the variables like this:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "segueFromVC1ToVCIWant"){
let viewControllerIWant = segue.destinationViewController as! ViewControllerIWant
ViewControllerIWant.variable0 = self.variable0
ViewControllerIWant.variable1 = self.variable1
}
}
Make sure you create variables with the same name in ViewControllerIWant in order to receive the values.

Related

Hide view while push to tabBar - swift

I have a view controller like below.
This view is attached with a tabBarController. The tabBarController has 5 viewControllers and I have to present the 5th viewController of tabBar from another page. So I used the below codes for present that viewController
#IBAction func onClickUserProfile(_ sender: Any) {
let navVc = self.storyboard?.instantiateViewController(withIdentifier: "ProfileVC")as! ProfileVC
navVc.userId = Int(self.userId)
navVc.navigationItem.hidesBackButton = true
navVc.tabBarController?.tabBar.isHidden = false
self.navigationController?.pushViewController(nxtVc, animated: true)
}
But after execute the code it resulting the view controller as the below image.
The view undergoes the tabBar. Anyone help me to push to a tabBar view.
You need to set the selected UIViewController from UITabBarController something like this should work .
self.tabBarController?.selectedViewController = self.tabBarController?.viewControllers![1]
where tabBarController?.viewControllers returns the array of current ViewControllers embedded in the UITabBarController .
Your code should be something like this.
#IBAction func onClickUserProfile(_ sender: Any) {
let vc = self.tabBarController?.viewControllers![1] as! ProfileVC // use your index
vc.userId = Int(self.userId)
self.tabBarController?.selectedViewController = vc
}
Note: Don't create an instance of the UIViewController as .instantiateViewController(withIdentifier:) use the already existed
ones in the array tabBarController?.viewControllers, creating new
instance will be treated as new one and gives the problem you have up
there .

Trigger segue in another UITabBarController VC with payload?

I can swap from one UIViewController to another within a UITabBarController using tabBarController?.selectedIndex = targetIndex. I would like to know how to trigger a segue after the switch.
I have tried doing if let vc = tabBarController?.viewControllers?[0] as MyViewController {} and calling vc.performSegue() but it errors out, complaining that it's a UINavigationController. (I couldn't even get vc.prepare() to work but I can't work out how to create a UIStoryBoardSegue, which it requires as the first argument, from scratch using the segue identifier.) I think this is because all of my UIViewControllers in the UITabBarController are within Navigation Controllers.
How do I switch from index 0 to 1 in the tab bar controller, and then trigger a segue in the view controller embedded in the navigation controller? Note, I need to pass in a copy of the calling object (my UIViewController) or a payload for contextual purposes to the UIViewController being segued to.
Well like you said the viewController which is presented at the index is a UINavigationController. You should get the rootViewController of the UINavigationController and perform the Segue on the RootViewController.
Below code should work:
self.tabBarController?.selectedIndex = 1
guard let vc = self.tabBarController?.viewControllers?[1] as? UINavigationController else {
return
}
guard let rootVC = vc.viewControllers.first as? SecondViewController else {
return
}
rootVC.vc = self
rootVC.performSegue(withIdentifier: "test", sender: self)

Swift ios send user to a specific ViewController in tab based application

I want to send a user to a specific ViewController in my app once a notification is clicked.
I now that I can do something like this:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let destinationViewController = storyboard.instantiateViewControllerWithIdentifier("Home") as? HomeViewController
presentedVC?.presentViewController(destinationViewController!, animated: true, completion: nil)
But my app has a tab bar and looks like this
Tab bar
tab1: navigationController -> VC1
tab2: navigationController -> VC2 -> HomeVC
tab: navigationController -> VC3
Each tab has a navigationController as a infront of it.
So how can I send the user to HomeVC? I must first select tab 2 then the navigation controller then push the user tvice:
tab2: navigationController -> VC2 -> HomeVC
And the other problem, if there any way to tell if the user is already in HomeVC? I dont want to send the user to the same VC if his already there.
You must have access to your UITabbarController in you UIApplicationDelegate or wherever you're handling the notification tap.
let tabBar:UITabBarController = self.window?.rootViewController as! UITabBarController //or whatever your way of getting reference is
So first you'll get the reference to UINavigationController in your second tab like this:
let navInTab:UINavigationController = tabBar.viewControllers?[1] as! UINavigationController
Now push your home view at second tab's navigation controller:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let destinationViewController = storyboard.instantiateViewControllerWithIdentifier("Home") as? HomeViewController
navInTab.pushViewController(destinationViewController!, animated: true)
And finally switch your tab to second to show the just pushed home controller
tabBar.selectedIndex = 1
Keep in mind, this answer assumes that your application has already set the tab bar as the root view controller of application window prior handling the notification tap.
Try something like this:
if let tabBarController = window?.rootViewController as? UITabBarController {
tabBarController.selectedIndex = 1 // in your case the second tab
}
The idea is to switch to get the tab bar instance and switch it to your desired tab (where you have your view controller).
The above code works in AppDelegate / you can easily call it anywhere by getting the tabBarController instance.
You can check which tab is selected by user with the method var selectedIndex: Int. You can check which view controller is present like this self.navigationController?.presentingViewController?.presentedViewController. This will solve your problem.

Segue To Same View Controller Programmatically?

Is there a way to segue to the same view controller in Swift? There is an answer for this in Objective-C but I can't convert it to Swift
UPDATE: I was able to push to the same viewcontroller but it immediately errors because it doesn't recognize the objects that were created on the storyboard
let aViewController:myVC = myVC()
self.navigationController!.pushViewController(aViewController, animated:false)
On the Load of the new(same) view controller it errors on the first line:
myText.editable = false;
Set an identifier for your UIViewController in the storyboard. Then instantiate it using that my identifier:
let storyboard = UIStoryboard(name: "MyStoryboardName", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "someViewController")
If you want to set variables, make sure to cast vc. This example will help you know how many levels deep you are on the same controller:
let vc = storyboard.instantiateViewController(withIdentifier: "rootViewController") as! MyRootViewController
vc.level = self.level + 1
I don't do much in swift, but looking at that answer, using self.navigationController?.pushViewController(viewController, animated:true)
should work.
First you connect your button for reloading with ViewController and give segue identifier a name (for instance "yourIdentifier")
Then you need to use:
override func prepare(for segue: UIStoryboardSegue, sender: Any?){
if segue.identifier == "yourIdentifier"{
self.viewDidLoad()
}
This should help.

transitioning from one view controller to another using a button

So, I created a login page with basic logic. If username and/or password are empty, it displays an error message. If they're full, then it transitions to the next page (home). I created a second ViewController on the storyboard, and created a SecondViewController". I then defined the respective ViewController class to "SecondViewController".
On the first ViewController.swift file, i used this code:
func transition(Sender:UIButton!)
{
let secondViewController: SecondViewController = SecondViewController()
self.presentViewController(secondViewController, animated:true, completion:nil)
}
When I tested it out however, pressing the login button (when both the username and password are filled) transfers me to a black screen instead of the second View Controller. Any ideas on what to do?
If you want the view to contain things added to it on the storyboard, you could give it a Storyboard ID (a couple of boxes below where you set the class of the view controller in the storyboard).
If you give it for example the ID "secondVC" you can then create it using the following:
let secondViewController = storyboard?.instantiateViewControllerWithIdentifier("secondVC") as? SecondViewController
You can't initialize a view controller with just the default init method.
You should probably create a view controller scene in your storyboard, add a unique identifier on it, instantiate it using instantiateViewControllerWithIdentifier:, and then display it like you are doing.
You'll want to make a segue between the view controllers in your Storyboard, and call self.performSegueWithIdentifier().
Or you can give your `UIViewController an identifier and present it programmatically too:
let storyboard = UIStoryboard(name: "MyStoryboardName", bundle: nil)
let secondViewController storyboard.instantiateViewControllerWithIdentifier("") as? SecondViewController
if let secondViewController = secondViewController {
self.presentViewController(secondViewController, animated:true, completion:nil)
}
There are basically three ways to do this
1)Creating segue in storyboard,though it will only work if you have single segue from that item
2)using prepareforSegue and performSegue Methods in your presenting view controller
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "YourIdentifier" {
let controller = segue.destinationViewController as!secondViewController
}
}
Then use this in your IBACtion
performSegueWithIdentifier("YourIdentifier", sender:sender)
3)(Recommended One)
let controller = self.storyboard?.instantiateViewControllerWithIdentifier("ContactsVC")! as! ContactsVC
self.presentViewController(controller, animated:true, completion:nil

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