I created a Mac OS X application in Xcode using storyboards. For some reason the applicationDidFinishLaunching method in the AppDelegate is being called after viewDidLoad in the NSViewControllers. As with iOS apps, I thought viewDidLoad is supposed to be called before applicationDidFinishLaunching? Do storyboards in OS X apps initialize the view controllers before the app has finished launching?
I am using the applicationDidFinishLaunching method to register default settings into NSUserDefaults. Unfortunately, registering the default values is happening after the views in the storyboard are loaded. Therefore, when I set up the view in each view controller using viewDidLoad, the defaults data in NSUserDefaults has not been set. If I can't use applicationDidFinishLaunching to register NSUserDefaults in OS X storyboard apps, then how I set the defaults before viewDidLoad is called?
To fix this issue, in the Main.storyboard in Xcode, I turned off "Is Initial Controller" for the main window. I assigned a storyboard ID to the main window as "MainWindow". Then in the AppDelegate I entered the following code:
import Cocoa
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
func applicationDidFinishLaunching(aNotification: NSNotification) {
let storyboard = NSStoryboard(name: "Main", bundle: nil)
let mainWindow = storyboard.instantiateControllerWithIdentifier("MainWindow") as! NSWindowController
mainWindow.showWindow(nil)
mainWindow.window?.makeKeyAndOrderFront(nil)
}
}
The app does not crash but now the window never appears. The following image displays the storyboard I'm working with:
Correct, the lifecycle is a wee bit different in OS X.
Instead of letting the storyboard be your initial interface (this is defined in the General settings of your project), you can instead set up a MainMenu xib file and designate that as your main interface, then in your applicationDidFinishLaunching method in your AppDelegate you can programmatically instantiate your storyboard after you have completed your other initialization code.
I recommend checking out Cocoa Programming for OS X: The Big Nerd Ranch Guide if you haven't already; one nice thing they do in their book is actually have you get rid of some of the default Xcode template stuff and instead they have you set up your initial view controller the "right" way by doing it explicitly.
You might put something like this in your applicationDidFinishLaunching:
NSStoryboard *mainStoryboard = [NSStoryboard storyboardWithName:#"Main" bundle:nil];
MyWindowController *initialController = (MyWindowController *)[mainStoryboard instantiateControllerWithIdentifier:#"myWindowController"];
[initialController showWindow:self];
[initialController.window makeKeyAndOrderFront:self];
This assumes that you've already changed "Main Interface" to something like MainMenu.xib.
As the question's author mentioned:
The app does not crash but now the window never appears.
Despite Nicolas and Aaron both helpful answers (I already adquire the book you recommended, Aaron, and will start implementing the two-storyboard pattern your way, Nicolas), neither solve the specific problem of the window not showing.
Solution
You need make your WindowController instance live outside applicationDidFinishLaunching(_:)'s scope. To accomplish it, you could declare a NSWindowController propriety for your AppDelegate class and persist your created WindowController instance there.
Implementation
In Swift 4.0
import Cocoa
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
var mainWindowController: NSWindowController?
func applicationDidFinishLaunching(_ aNotification: NSNotification) {
let storyboard = NSStoryboard(name: NSStoryboard.Name(rawValue: "Main"), bundle: nil)
let mainWindow = storyboard.instantiateController(withIdentifier: NSStoryboard.SceneIdentifier(rawValue: "MainWindow")) as! NSWindowController
mainWindow.showWindow(self)
mainWindow.window?.makeKeyAndOrderFront(self)
// After applicationDidFinishLaunching(_:) finished, the WindowController instance will persist.
self.mainWindowController = mainWindow
}
}
In addition to Aaron's answer, I found out that the separate Interface Builder file containing the menu alone (separate from the window and view controller) does not need to be a xib; it too can be a storyboard. This enables us to easily fix as follows:
Duplicate your original storyboard (Main.storyboard) and rename it to "Menu.storyboard"
Delete the window controller and view controller from Menu.storyboard
Delete the app menu bar from Main.storyboard.
Change your app target's "Main Interface" from "Main.storyboard" to "Menu.storyboard".
(I tried it in my app and it works)
This avoids having to re-create the app's main menu from scratch, or to figure out how to transplant your existing one from "Main.stroyboard" to "Menu.xib".
The other solution is registering NSApplicationDidFinishLaunchingNotification in your view controllers and move your code from viewDidLoad to applicationDidFinishLaunchingNotification:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationDidFinishLaunchingNotification:)
name:NSApplicationDidFinishLaunchingNotification
object:nil];
Based on my previous answer here
If you want a piece of code to be run before everything, you can override the AppDelegate's init() like this:
#main
class AppDelegate: UIResponder, UIApplicationDelegate {
override init() {
DoSomethingBeforeEverthing() // You code goes here
super.init()
}
...
}
Few points to remember:
You might want to check, what's allowed/can be done here, i.e. before app delegate is initialized
Also cleaner way would be, subclass the AppDelegate, and add new delegate method that you call from init, say applicationWillInitialize and if needed applicationDidInitialize
Using Swift 1.1 and Xcode 6.2.
I have a UIStoryboard containing a singular, custom UIViewController subclass. On it, I have an #IBOutlet connection of type UIView from that controller to a UIView subclass on the storyboard. I also have similar outlets for subviews of that view. See figure A.
But at run time, these properties are nil (Figure B). Even though I have assured I've connected the outlets in Interface Builder.
Thoughts:
Is it possible that because I am using a subclass of a subclass something messes up with the initialization? I am not overriding any initializers
awakeFromNib: is not getting called for some reason
Maybe it doesn't connecting to subviews on subviews
Things I have tried:
Matching #IBOutlet and storyboard item types exactly (instead of UIView)
Deleting property and outlet and re-added them
Figure A*
Figure B
*The obscured code in Figure A is:
#IBOutlet private var annotationOptionsView: UIView!
#IBOutlet private var arrivingLeavingSwitch: UISegmentedControl!
Thank you.
Typically this happens because your view controller hasn't loaded its view hierarchy yet. A view controller only loads its view hierarchy when something sends it the view message. The system does this when it is time to actually put the view hierarchy on the screen, which happens after things like prepareForSegue:sender: and viewWillAppear: have returned.
Since your VC hasn't loaded its view hierarchy yet, your outlets are still nil.
You could force the VC to load its view hierarchy by saying _ = self.view.
Did you instantiate your view controller from a Storyboard or NIB, or did you instantiate it directly via an initializer?
If you instantiated your class directly with the initializer, the outlets won't be connected. Interface Builder creates customized instances of your classes and encodes those instances into NIBs and Storyboards for repeated decoding, it doesn't define the classes themselves. If this was your problem, you just need to change the code where you create your controller to instead use the methods on UIStoryboard, or UINib.
Have you tried running Product > Clean. Solved a very similar problem for me.
The storyboard wasn't recognizing any further UI things I added to it. At run time all the references were nil. So I cleared my derived data folder and then those connections worked again.
This happened for me because I was accidentally instantiating my view controller directly instead of instantiating it through the storyboard. If you instantiate directly via MyViewController() then the outlets won't be connected.
This was happening to me with my custom collection view cell. Turns out I had to replace my registerClassforReuseIdentifier method with registerNib. That fixed it for me.
In my case, it happened because I overriden the loadView method in my ViewController subclass, but forgot to add [super loadView]
-(void)loadView {
// blank
}
When you override the loadView method, the it is your responsibility to init your subviews. Since you override it, the views from interface builder do not get the chance to convert to cocoa objects and thus outlets remain nil.
If you implement loadView in your view controller subclass, then it becomes your responsibility load the UI elements from from storyboard/xib into code.
Or just call
[super loadView];
So that the superclass gets the chance to load storyboard/xib into code.
If you instantiate view controller through programmatically. Then
try creating it like below
let initialVC = self.storyboard?.instantiateViewController(withIdentifier: "InitialVC") as! InitialVC
instead of directly
let initialVC = InitialVC()
This worked for me.
You can call controller.view to force to load the view to initialize the IBOutlets, then you will be able to assign the values.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
if (segue.identifier == "identifier") {
let controller = segue.destinationViewController as! YourController
let _ = controller.view //force to load the view to initialize the IBOutlets
controller.your_IBOutlet_property = xxx
...
controller.delegate = self
}
}
I encounter this problem recently! Here is my thought.
The problem is not about you storyboard or any link issue. It is about how you initiate your ViewController. Especially when you are using Swift.(There is barely nothing in the editor when you create a class file)
By simply using the init() from super class can not initiate anything you worked with story board. So what you need to do is changing the initialisation of the ViewController. Replace
let XXViewController = XXViewController()
by
let XXViewController = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateViewControllerWithIdentifier("XXViewController") as! XXViewController
This tells the program to go to the storyboard find XXViewController and initiates all IBOutlet in your storyboard.
Hope this help~ GL
For me, this occurred when I accidentally declared my view controller's class as
class XYZViewController: UINavigationController {
}
(ie as a UINavigationController not a UIViewController).
Xcode doesn't pick up on this mistake, the class seems to build fine, and override functions such as viewDidLoad, viewWillAppear, etc. all work correctly. But none of the IBOutlets get connected.
Changing the declaration to
class XYZViewController: UIViewController {
}
fixed it completely.
2019, ONE POSSIBILITY FOR THIS HORRIBLE PROBLEM:
Say you have perhaps a container view that shows some sort of clock. So you have
class Clock: UIViewController
You actually use it in a number of places in the app.
On the main screen, on the details screen, on the edit screen.
You have a complicated snapchat-like modern app.
In fact, Clock may actually be loaded more than once at the same time somewhere on the same screen. (Maybe it's hidden in some cases.)
You start working on one instance of Clock on one of your many storyboards.
On that storyboard you add a label, NewLabel.
Naturally you add the outlet in code. Everything should work. All the other outlets work perfectly.
You have definitely linked the outlet.
But the app crashes with NewLabel as nil.
Xcode clearly tells you "you forgot to connect the outlet".
The reason is this .......... you have "NewLabel" on only one of the storyboard uses of Clock!
The crash is actually from >>> an other place <<<< you are using Clock!!!!
Xcode does not tell you the crash is from another place altogether, not from where you are working!
The crash is actually not from the place you are working - it's from another storyboard, where there is no "NewLabel" item on that storyboard!!!
Frustrating.
For Swift 3.
func configureView() {
let _ = self.view
}
In my case, the app started crashing all of a sudden.
Debugging it revealed that all outlets were still nil at the time of viewDidLoad().
My app still uses nibs (not storyboards) for most view controllers. Everything was in place, all outlets wired properly. I double-checked.
We typically instantiate our view controllers as
let newVC = MYCustomViewController()
...which for some reason seems to work as long as the .xib is named the same as the view controller class (not sure how that works, though. We are not calling init(nibName:bundle:) with nil arguments, or overriding init() to do so on self like it is typically suggested...).
So I tried to explicitly call
let newVC = MYCustomViewController(nibName: "MYCustomViewController", bundle: .main)
...only to be greeted with the runtime exception error:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle </Users/nicolasmiari/Library/Developer/CoreSimulator/Devices/3DA3CF21-108D-498F-9649-C4FC9E3C1A8D/data/Containers/Bundle/Application/C543DDC1-AE86-4D29-988C-9CCE89E23543/MyApp.app> (loaded)' with name 'MYCustomViewController''
And then, I saw it:
The "Target Membership" checkbox of the .xib file was unchecked.
Must have happened when resolving one of the frequent merge conflicts regarding the Xcode project file.
Apple definitely needs to come up with a project file format that is more SCM-friendly.
You need to load the view hierarchy first in order to instantiate the outlets in the storyboard. For this, you can manually call the loadView or loadViewIfNeeded methods.
100% Working solution for creating ViewControllers from XIB without StoryBoards
Create class CustomViewController : UIViewController
Create view CustomViewControllerView.xib
In CustomViewControllerView.xib in Interface Builder select Placeholders -> File's Owner
In "Attributes inspector" set Class to CustomViewController
In "Connections inspector" connect "view" to top-level view of xib (ensure top-level view's Class is not pointing to CustomViewController)
In "Connections inspector" connect other outlets (if needed/exist)
Create an instance of CustomViewController in parent view controller/App delegate
7.1.
// creating instance
let controller = CustomViewController()
7.2.
// connecting view/xib with controller instance
let bundle = Bundle(for: type(of: controller))
bundle.loadNibNamed("CustomViewControllerView", owner: controller, options: nil)
7.3.
// get/set outlets
controller.labelOutlet.text = "title"
controller.imageOutlet.image = UIImage(named: "image1")
Check your IBOutlet connection if it connected to the File owner or the view.
There could be mistakes.
Other case:
Your outlets won't get set until the view controller's view is actually instantiated, which in your case is probably happening shortly after initWithNibName:bundle:—at which point they'll still be nil. Any setup you do that involves those outlets should be happening in your view controller's -viewDidLoad method.
For me, I had same error on a localized storyboard, an element was added in some locale and not in the other, so I had null reference for that element when switched to the missing element locale, I had to remove (redundant) localization for that storyboard using https://stackoverflow.com/a/42256341/1356559.
For me, this was crashing because containerView was nil.
Here is my code with Crash.
#IBOutlet private var containerView: UIView! // Connected to Storyboard
override open func loadView() {
containerView.addSubview(anotherView)
}
The missing thing was calling the super.loadView(). So adding it solved problem for me.
Fixed Code:
#IBOutlet private var containerView: UIView!
override open func loadView() {
super.loadView()
containerView.addSubview(anotherView)
}
I had a similar issue when I had previously added register(_:forCellReuseIdentifier:) for the custom cell after I had already defined the identifier in the storyboard. Had this code in the viewDidLoad() function. Once I removed it, it worked fine.
Yet another case I just ran into. I changed the name of my class for the UIViewController, but I forgot to change the name of the .xib file where the interface was built.
Once I caught this and made the file names reflect the class name, it was all good!
I hope that helps someone.
Got one more ...
If you have a custom class for a UITableViewCell but forget to specify Custom in the Style of the cell.
Check to see if you have any missing or disconnected outlets.
You can validate if the is view is loaded.
if isViewLoaded && view.window != nil {
//self.annotationOptionsView.
}
select both .h and .m view controller files
remove the reference of those files
re-add the files to your project tree
open the storyboard, eventually re-build the project
Accidently I subclassed my view controller with AVPlayerViewController instead of UIViewController. By replaying it to UIViewController things back normal. This should help.
No build cleaning (normal&full), removing derived data folders and quitting Xcode worked for me.
I had the same problem after copying a class (linked to a xib) to reuse it with another viewcontroller class (linked to a storyboard).
I forgot to remove
override var nibName
and
override var nibBundle
methods.
After removing them, my outlets started to work.
I see you use ViewController!? in ViewController class you must use -viewDidLoad, not -awakeFromNib, -awakeFromNib use for UIView class
If you have two main.storyboards and you are making changes to the wrong one this can happen. This can happen anytime you connect an outlet from an uninstantiated storyboard.
I am working on a Yosemite app in swift and have hit a road block.
I have multiple views working properly, and now I want to implement custom menu actions. To keep the answer simple, how would I achieve this example. I want to click a menu button and have it change text on the viewcontroller. I have tried setting up IBActions, but I'm not sure how to make the link to the viewcontroller from the AppDelegate. How do you connect the two?
I'm still figuring this stuff out, so any insight would be awesome. Thanks in advance.
*UPDATE. I tried making a object and linking it that way. No luck.
When you press "Test" it prints test, however it's in it's own class. I need to do something in my main ViewController class. How to I make that reference?
Getting NSViewController from NSWindow is an easy solution.
If your app has multiple windows, select appropriate one through keyWindow or windows of NSApplication.
#IBAction func pressed(sender: AnyObject) {
if let window = NSApplication.sharedApplication().mainWindow {
if let viewController = window.contentViewController as? YourViewController {
// do stuff
...
}
}
}
On my main window I have a CustomView. Depending on what the user selects, this view will be changed. To have a clear source code, I created for each new view a NSViewController with a new xib file. Then I connected my IBOutlets to the new ViewControllers. This works perfect. But if I add an IBAction, Xcode says, that it cannot connect to the action. So I googled and I found out, that I should not connect all the IBOutlets and IBActions to the File's Owner of the ViewController. Instead I added a new NSObject to the new xib file and set the Class to my ViewController class. If I now want to access the IBOutlets, I'm getting the error fatal error: Can't unwrap Optional.None at the line, where I want to access the IBOutlet.
Any ideas? What's the right way to work with NSViewControllers. Do I have to add an NSObject? How many instances of my ViewController are then created?
"Can't unwrap Optional.None" is what happens when you have an implicitly unwrapped optional (one defined with an !) that is nil but you try to use it anyway. For example:
var aNumber : Int! = nil
aNumber + 5 //fatal error: Can't unwrap Optional.None
I believe outlets are declared as implicitly unwrapped by default in Swift, so you're probably getting this error by trying to do something with an outlet that isn't connected in interface builder (or your storyboard or whatever).
As to the rest, it's really hard to understand what you're doing in your app. I understand you have an NSViewController for each view, but what outlets are you connecting to them? Where are you adding the IBAction? Which file's owner do you mean, the owner of the window's nib? The owner of your NSViewControllers?
It sounds to me like you're making this way too complicated, and adding more NSObjects to the mix is almost certainly the wrong way to go. See if you can simplify things or upload your project someplace so we can take a look and better diagnose your issue.
I now have the solution. Here is the way to use NSViewController: (working in Beta 3)
Create a new app and add a CustomView to the main window. Connect this custom view to your AppDelegate.
Add this var to your AppDelegate: var mainViewController: NSViewController?
Create some new Swift Cocoa Classes as Subclasses of NSViewController and check "Also create XIB file for user interface" as much as you need.
For each ViewController add a new variable to AppDelegate like this: var firstVC = firstViewController(nibName: "firstViewController", bundle: nil)
Now edit your new xib files and connect everything to the correspondig swift file.
For changing the view and the view controller, choose this code:
mainViewController?.view.removeFromSuperview()
mainViewController = firstVC //or the vc you need
customView.addSubview(mainViewController?.view)
mainViewController?.view.setFrameSize(customView.bounds.size)
That's all. All IBActions and IBOutlets now work without any error. If you need a method for doing some things on loading the view, take override func loadView() { super.loadView() ...
I've just played around with the new mac storyboard-feature included in Xcode 6. I've set up a new OS X-project using storyboards and swift, then I've created a new file MainWindowController.swift, created the initializer init(coder: NSCoder!) (because otherwise the compiler warns me) and hooked everything up in the Main.storyboard file (set the MainWindowController-class for the WindowController in the inspector).
Everything compiles fine, my Window with the specified window content-view opens. But the code I've written in the windowDidLoad-function is never be called. Let it just something like:
override func windowDidLoad() {
super.windowDidLoad()
println("Executed")
}
I've also tested if my initializer is called - it is.
Does anybody has a clue? I've never used storyboards intensively on iOS before, maybe I miss something substantial.
In Yosemite, NSViewController has been promoted with powerful new features to make it work with Storyboards. Meanwhile, NSWindowController got demoted. With Storyboards, windows are no longer loaded from a nib, so windowDidLoad() doesn't get called anymore.
It makes sense for the window itself to become less important, in favor of a more powerful view it actually contains. My other answer on this page shows how to set up an AppDelegate to customize the window appearance. There's more detail on another page here, about using an AppDelegate to implement some of the things you might previously have done in an NSWindowController.
However, if you only wanted to catch windowDidLoad() as a way to customize the appearance options of the window, it is very easy to do that in Interface Builder, by simply adding them as User Defined Runtime Attributes to the NSWindow object. You don't need to subclass NSWindowController or write any code at all. Just plug in these values to the NSWindow object via the Identity Inspector pane to achieve the same effect shown in the AppDelegate example code:
Keypath: titlebarAppearsTransparent, Type: Boolean, Value: Checked
Keypath: titleVisibility, Type: Number, Value: 1
Keypath: styleMask, Type: Number, Value: 32783
Look in the headers to determine the actual numeric values of the constants.
( for example: NSWindowTitleVisibility.Hidden = 1 )
Of course, you can't specify individual bits of the styleMask, but it's easy enough to add them all together and get a single number to specify the style.
Remove everything except the Application scene from the Main.storyboard file, and instead, create a new Application.storyboard for the application window. Implement an application delegate class and connect it to the Application object in Main.storyboard. Use this class to instantiate the window controller and set up custom options for the application window.
class AppDelegate: NSObject, NSApplicationDelegate {
func applicationDidBecomeActive(notification: NSNotification) {
let storyboard = NSStoryboard(name: "Application", bundle: nil)
applicationController = storyboard.instantiateInitialController() as? NSWindowController
if let window = applicationController?.window {
window.titlebarAppearsTransparent = true
window.titleVisibility = NSWindowTitleVisibility.Hidden
window.styleMask |= NSFullSizeContentViewWindowMask
applicationController!.showWindow(self)
}
}
}
Rather than subclassing NSWindowController, use the ViewController.swift subclass of NSViewController that Xcode creates for you automatically with the project.
In the storyboard, notice how there's a Relationship that connects the "window content" to the ViewController. So, the ViewController can now do things that you might previously have done in a window controller.
The ViewController.swift file will already have a default override of viewDidLoad() that will be called when the window loads, just as you were expecting windowDidLoad() to be called if it were an NSWindowController subclass.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
println("Executed")
}