I am really struggling with what should be a simple bit of code.
I have an ios app that has 4 tabs in the uitabcontroller, depending on the a setting in another tab I wanted to replace the controller the first tab goes to. I found that I couldnt simply replace this first tab (although i managed it somehow for a couple of builds then it stopped working after a clean).
So I went for the option of replacing the viewcontrollers that the tab controller references with the .setViewControllers method. I call this from my viewcontroller after the viewdidload method.
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc0 = storyboard.instantiateViewControllerWithIdentifier("collection")
let vc4 = storyboard.instantiateViewControllerWithIdentifier("profilenews1")
let vc1: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("news") as UIViewController
let vc2: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("create") as UIViewController
let vc3: UIViewController! = storyboard.instantiateViewControllerWithIdentifier("search") as UIViewController
let controllers = [vc0,vc4]
self.tabBarController?.setViewControllers(controllers, animated: true)
From the research I have done this should work, setViewControllers is documented and I have seen numerous objective c examples but I get EXEC_BAD_INSTRUCTION thrown.
I have checked that the tabcontroller is correct before I replace by doing
println("number of navs: \(self.tabBarController?.viewControllers?.count)")
And that prints the correct number of controllers.
Any ideas?
Related
I am working on making a tabbed app. It has a TabBarController and 4 ViewControllers attached to it.
By default, at launch only FirstViewController is loaded. I would like to load both FirstViewController and SecondViewController at start before switching to the second view via tab menu.
What i tried so far is that I created custom MyTabBarController class and tried to use
var sv = SecondViewController()
sv.loadView()
in ViewDidLoad(), but it caused a fatal error during loading, because (my guess) mapView element from storyboard was not loaded.
What is the correct way to simultaneously load the two viewControllers which use storyboard elements? All my other tries have not been successful so far.
Add in your main view controller
var secondViewController:UIViewController!
And in your viewDidLoad:
secondViewController: UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "yourIdentifier") as! SecondViewController
That's it. When you want to present it, use:
self.present(secondViewController, animated: true, completion: nil)
In my app I use side bar as in facebook. when the user slides out the side bar a uiimageview is displayed. when user taps on the image it takes hm to a different viewcontroller. the problem i am facing is that I have created sidebar programatically and the other view to which I want to navigate the user is created using storyboard. So my source view is created programatically and destination view is created using storyboard. So can someone explain me if there is any way of using "Segue" in this scenario. Since i can not create segue using storyboard I need to do it programatically but even after a lot of googling i could not find the answer.
Well, to get another instance of another storyboard programmatically you can use something like:
let newController = UIStoryboard(name: "MyStoryboard", bundle: nil).instantiateViewControllerWithIdentifier("MyIdentifier") as! MyViewController
and then you push to your navigation controller, or add as a child view controller or something...
If you don't wanna bother with identifiers you can just use the instantiateInitialViewController instead of instantiateViewControllerWithIdentifier
Might help
"userSB" is the viewcontroller storyboard identifier
#IBAction func tapSearchCriteria(_ sender: Any?) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let aVC = storyboard.instantiateViewController(withIdentifier: "userSB") as? AViewController
aVC?.modalPresentationStyle = UIModalPresentationStyle.custom
aVC?.transitioningDelegate = self
aVC?.udelegate = self
self.present(aVC!, animated: true, completion: nil)
}
I read a lot of questions / answers in the stack overflow community about switching between different ViewControllers but I couldn't find the correct answer for my specific problem.
I'm using a NavigationViewController to "connect" all my different viewControllers (ViewController / TableViewController / CollectionViewController)
I have got some classes which aren't depending on a ViewController class. For example to to calculate anything in my "calculate" class.
I'm searching for an easy solution, to switch between all my ViewControllers. And I would like to decide in my "calculate" class e.g. to go one step back in my Navigation ViewController.
In the moment I use this:
Example to switch between two different ViewControllers:
let sb = UIStoryboard(name: "Main", bundle: nil)
let vc = sb.instantiateViewControllerWithIdentifier("StartPage") as! StartPageView
self.presentViewController(vc, animated: true, completion: nil)
PROBLEM: This example only works in a ViewController class and the navigation bar disappears.
Example to go one step back in my NavigationViewController:
self.navigationController?.popViewControllerAnimated(true)
PROBLEM: This example only works in a ViewController class.
EDIT 1:
I found a nice solution to call all my viewControllers with this part of code:
let switchViewController = self.navigationController?.viewControllers[1] as! ScanTableView
self.navigationController?.popToViewController(switchViewController, animated: true)
How can I call this code in a non ViewController class?
Push the new view controller onto your existing navigation stack, rather than presenting it modally:
let vc = self.storyboard!.instantiateViewControllerWithIdentifier("StartPage") as! StartPageView
self.navigationController!.pushViewController(vc, animated: true)
There is a great blog post over at http://www.appcoda.com/tag/swrevealviewcontroller/ that goes in to setting up SWRevealViewController which is a great component for slide out side menus (https://github.com/John-Lluch/SWRevealViewController)
Unfortunately, there are no swift examples of how to perform a manual segue.
Took a cleaner approach to storyboard support. SWRevealViewControllerSegue is now deprecated and you should use SWRevealViewControllerSegueSetController and SWRevealViewControllerSeguePushController instead.
I've tried something along the lines of:
let navigationController = self.window?.rootViewController as! SWRevealViewController;
let viewController = navigationController.storyboard?.instantiateViewControllerWithIdentifier("ImportFileSelect") as! ImportFileSelect
navigationController.showViewController(viewController, sender: self)
This doesn't work though. Any ideas? I've trawled the web for swift examples, my next step is to learn objective c!
In order to work you'll need to following steps:
You need to instantiate the SWRevealViewController and then attach it
to the root controller.
Then instantiate the destination controller.
Then create a navigation controller and set the destination
controller as the rootViewController
Finally push the navigation controller with SWReveal
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let sw = storyboard.instantiateViewControllerWithIdentifier("SWRevealViewController") as! SWRevealViewController
self.view.window?.rootViewController = sw
let destinationController = self.storyboard?.instantiateViewControllerWithIdentifier("StoryboardID") as! NameOfViewController
let navigationController = UINavigationController(rootViewController: destinationController)
sw.pushFrontViewController(navigationController, animated: true)
I've kind of made some progress. I can load in a new view controller, but it doesn't animate in anyway. The code to do this, on a button click is:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("TARGET_VIEW_CONTROLLER") as! UIViewController
var rvc:SWRevealViewController = self.revealViewController() as SWRevealViewController
rvc.pushFrontViewController(vc, animated: true)
Download SWRevealViewController project's zip form Github.
Drag SWRevealViewController.m and SWRevealViewController.h files from zip (SWRevealViewController folder) to your project, and Click “Yes” to the prompted message "Would you like to configure an Objective-C bridging header?"
Take a look at storyboard in RevealControllerStoryboardExample2 project. Design your storyboard with this example.
This is not how it should be done, but at least i found a way to do it.
In the TableViewController where u have the slideOut menu do something like:
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if(indexPath.row == <some position> ){
let vc: AnyObject! = self.storyboard?.instantiateViewControllerWithIdentifier("YOUR_DESTINATION_IDENTIFIER")
self.showViewController(vc as! SWRevealViewController, sender: vc)
}
The one that satisfy the condition will segue with default animation, not like the slide out menu normally does.
After, in storyboard, do a normal Reveal View Controller Push controller, and as long as it doesn't satisfy the condition it will exit the slide out menu normally
I am trying to add some unit tests to my project to test view controllers. However I seem to be having problems with seemingly simple things. I have created a sample project which I will refer to. https://github.com/pangers/ViewControllerTesting
The sample contains a UINavigationController as the initial view controller. The root view controller of the UINavigationController is FirstViewController. There is a button on FirstViewController that segues to SecondViewController. In SecondViewController there is an empty textfield.
The two tests I am trying to add are:
1) Check button title in FirstViewController is "Next Screen".
2) Check textfield in SecondViewController is empty, "".
I have heard reports of adding your swift files to both the main target and the test target is not good practice. But rather it is better to make whatever you want to access in your tests public and import the main target into the tests. So that is what I have done. (I have also set the "Defines Module" for the main target to YES as that is what I have read in a few articles aswell).
In FirstViewControllerTests I have instantiated the first view controller with the following:
var viewController: FirstViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
viewController = navigationController.topViewController as FirstViewController
viewController.viewDidLoad()
}
And I have added the test:
func testCheckButtonHasTextNextScreen() {
XCTAssertEqual(viewController.button.currentTitle!, "Next Screen", "Button should say Next Screen")
}
Similarly, for SecondViewControllerTest, I have set it up using:
var secondViewController:SecondViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
let firstviewController = navigationController.topViewController as FirstViewController
firstviewController.performSegueWithIdentifier("FirstToSecond", sender: nil)
secondViewController = navigationController.topViewController as SecondViewController
secondViewController.viewDidLoad()
}
And the test:
func testTextFieldIsBlank() {
XCTAssertEqual(secondViewController.textField.text, "", "Nothing in textfield")
}
They both fail and I am not too sure as to why. My suspicion is that the way I am instantiating the view controllers is not correct. Is the best way to instantiate the view controllers is to use the storyboard (just like it would if it were to run in real life)? Or is it acceptable to be instantiated via:
var viewController = FirstViewController()
What are you guys' experience with TDD and view controllers in swift?
I am using Swift with XCode 6.1.1.
Thanks in advance.
Solved
Ok after considering the answers from modocache and Mike Taverne, I've found my solution and I've learnt a few things which I will write down below.
1) I made anything class/method/variable that I want to test public. I do not need to add the swift files to the test target.
2) I only needed to set "Defines Module" for the "Main" target (as opposed to the "Test" target or the entire project)
3) When instantiating the storyboard, the bundle should be set to nil rather than NSBundle(forClass: self.dynamicType), otherwise tests will fail.
4) As modocache stated, it is good to give your view controller's a StoryboardID and instantiate them like so:
viewController = storyboard.instantiateViewControllerWithIdentifier("FirstViewController") as FirstViewController
However, instantiating the view controller like this ONLY instantiates the view controller alone, and not any navigation controllers that it may be embedded in. That means, attempting to do
XCTAssertFalse(viewController.navigationController!.navigationBarHidden, "Bar should show by default")
will result in a nil exception. I confirmed this with
XCTAssertNil(viewController.navigationController?, "navigation controller doesn't exist")
which resulted in a successful test.
Since I wanted to check the state of the navigation bar in FirstViewController, you must instantiate the view controller like so:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let navigationController = storyboard.instantiateInitialViewController() as UINavigationController
viewController = navigationController.topViewController as FirstViewController
Now performing the test
XCTAssertFalse(viewController.navigationController!.navigationBarHidden, "nav bar should be showing by default")
results in a successful test.
5) let _ = viewController.view does indeed trigger viewDidLoad() which was confirmed by a test
6) let _ = viewController.view does not trigger viewWillAppear(), and I presume anything afterwards aswell. viewController.viewWillAppear(false/true) needs to be called manually to trigger it (Confirmed by a test).
Hopefully this will be of help to people. I will push the updated project to GitHub (link above) if anyone would like to play around with it.
Update #2
After all the above, I still could not figure out how to transition from the first view controller to the second view controller (so that I may test navigation bar properties in SecondViewControllerTests.swift). I tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
let firstVC = nc.topViewController as FirstViewController
firstVC.performSegueWithIdentifier("FirstToSecond", sender: nil)
secondVC = nc.topViewController as SecondViewController
which caused an error.
I also tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
let firstVC = nc.topViewController as FirstViewController
firstVC.toSecondVCButton.sendActionsForControlEvents(UIControlEvents.TouchUpInside)
secondVC = nc.topViewController as SecondViewController
which did not work.
I eventually tried
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let nc = storyboard.instantiateInitialViewController() as UINavigationController
vc = storyboard.instantiateViewControllerWithIdentifier("Second") as SecondViewController
nc.pushViewController(vc, animated: false)
let _ = vc.view
vc.viewWillAppear(false)
which worked perfectly with my tests (allowed me to access navigation bar properties)!
I agree with #MikeTaverne's answer: I prefer accessing -[UIViewController view] in order to trigger -[UIViewController viewDidLoad], rather than calling it directly. See if the test failures for FirstViewController go away once you use this instead:
viewController = navigationController.topViewController as FirstViewController
let _ = viewController.view
I'd also recommend giving both view controllers identifiers in your storyboard. This will allow you to instantiate them directly, without accessing them via UINavigationController:
var secondViewController: SecondViewController!
override func setUp() {
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle(forClass: self.dynamicType))
secondViewController = storyboard.instantiateViewControllerWithIdentifier("SecondViewController")
as SecondViewController
let _ = secondViewController.view
}
Check out my talk on testing UIViewController at Brooklyn Swift for details: https://vimeo.com/115671189#t=37m50s (my presentation begins around the 37'50" mark).
I've begun unit testing view controllers recently, and it poses some unique challenges.
One challenge is getting the view to load. Looking at your set up for FirstViewController, you are trying to do this with viewController.viewDidLoad().
My suggestion is to replace that line with this:
let dummy = viewController.view
Accessing the .view property will force the view to load. This will trigger the .viewDidLoad in your ViewController, so don't call that method explicitly in your test.
This approach is considered hacky by some people, but it is simple and effective. (See Clean way to force view to load subviews early)
As an aside, I am finding the best way to test view controllers is to move as much code out of the view controllers as possible into other classes that are more easily tested.
If your view controller is defined in a storyboard, then you need to instantiate it that way for your outlets to be set up properly. Trying to initialize it like an ordinary class won't work.