storyboard views are not connected while using an iOS library - ios

I am trying to implement a library(named: XLPagerTabStrip). Everything works fine with the help of this available tutorial [ https://github.com/xmartlabs/XLPagerTabStrip ].
My problem is: I can change my view controllers layout using code but i'm not able to change it through my storyboard; though the view controllers associated with the above library can be accessed. My storyboard views are well-connected with code.
Please help me get up from here. I'm stuck.

Solution :
Take the instance of the view controllers you wish to use inside MyPagerTabStripName( main controller class of library). In this way:
override internal func
viewControllersForPagerTabStrip(pagerTabStripController:
PagerTabStripViewController) -> [UIViewController] {
let firstVC = self.storyboard!.instantiateViewControllerWithIdentifier("myfirst") as! TabFirstViewController
let secVC = self.storyboard!.instantiateViewControllerWithIdentifier("mysecond") as! TabSecondTableViewController
return [firstVC, secVC]
}
Then you can access them using these identifiers in storyboard.

Related

Instantiation of ViewControllers from storyboard in Swift

I have a UIViewController that looks a bit like this:
class ProfileViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, ... {
...
convenience init(name: String) {
print("Init with student: \(name)")
self.init()
}
...
}
I have a corresponding Storyboard layout for this, embedded in a UINavigationViewController, linked to a UITabBarController. This seemed like the easiest way to design the layout, and is great for when there's only one instance of this VC required (which is how the app was originally designed).
I'd now like to create multiple tabs from this single design (between 1 and 3), and pass the VC init information programatically, but I'm unsure exactly of the best way to do this - as you can see above I've added a convenience init function based on some reading I've done as that seemed like a good place to start.
It's easy enough to create new named tabs based on the storyboard layout like this:
for user in (users)! {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "profileNC")
controller.tabBarItem.title = user.name
newTabs?.insert(controller, at: 0)
}
self.viewControllers = newTabs
But, doing it this way I don't get to call the init function to pass the UIViewController the information it needs to display correctly.
How can I create my ViewControllers, link the layout to the Storyboard and use the custom init function? Is this even possible?
Any suggestions gratefully appreciated!!
When using a storyboard you cannot use a custom initialiser. You will need to either set the property directly or use a configuration function on the view controller instance after you have created it.

How to pass data between Swift files without prepareForSegue?

I currently have three Swift files, one for the main view in a ViewController, and two more which are used for the two views within the first view, which are used for a Segmented Control.
As these don't use segues between each other, I can't use the prepareForSegue method to transfer data between them, so how do transfer the variables and such from one file to another?
This doesn't seem to be a duplicate as other cases such as the one commented are using segues, mine is not.
Are all three Swift classes view controller subclasses?
You have your main view controller with your segmented control. For each segmented, I would create a new view controller subclass.
On your main view controller, for each segment, use a 'Container View' instead of a UIView object.
This will create two new 'screens' in the storyboard, attached to your main view controller with a segue. These new screens will be UIViewControllers, you can change them to be your subclass's as normal.
You can now use your prepareForSegue function as normal to set data in your segmented control view controllers.
So you have something like viewControllerMain, which contains viewSegmentedOne and viewSegmentedTwo, and you want to be able to access `viewControllerMain.myProperty' ?
You can always navigate through the hierarchy to get parent views - but the easiest option could be to include a reference to viewControllerMain in each of the segmented controls
var myParentVC : ViewControllerMain?
then when you create the subviews
mySubView.myParentVC = self
If you are using storyboard for view controllers, then try like this:
let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Your_VC_Identifier");
viewController.Your_var = Your_value_to_assign
NOTE: Define Your_var in your ViewController class
You just need to create an instance of the view controller you want to display, this is easy such as calling on the storyboard instance (usually the presenting view controller has one) instantiateViewController(withIdentifier:), by using an identifier that you provide in the storyboard file.
One created you can pass the data you want by casting it to your view controller class and present it as you prefer.
One method would be using singleton class . https://cocoacasts.com/what-is-a-singleton-and-how-to-create-one-in-swift/ this is how you can make singleton class.
other method could be using nsuserdefaults.
You need to decide which approach is best according to your requirement.
try this:
let defaults = UserDefaults.standard()
defaults.set(yourdata, forKey: "someObject")
print(defaults.object(forKey: "someObject"))
You can try use Extensions for UIViewController
private var storedDataKey: UInt8 = 0
extension UIViewController {
var storedViewControllerData: UIViewController? {
get {
return objc_getAssociatedObject(self, &storedDataKey) as? UIViewController
}
set(newValue) {
objc_setAssociatedObject(self, &storedDataKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN)
}
}
}
This very useful you can send data with chain like:
viewControllerB.storedViewControllerData = viewControllerA.storedViewControllerData
or
func viewDidLoad() {
doSomething(self.storedViewControllerData)
}

Set initial viewController in Navigation controller programmatically (Layer SDK)

I want to add Layer SDK to my application (using Swift).
All view controllers here are created programmatically. Therefore I can't segue to them. I have 4 tabs in my application (UITabBarController). One of them is chat. In the chat tab I created a segue to UINavigationController. Now I want to load conversationListViewController in this UINavigationController. For that I created a class for this UINavigationController i.e. ConversationListViewController and added the following code:
class ChatNavigationViewController: UINavigationController {
var conversationListViewController: ConversationListViewController!
var layerClient: LYRClient!
override func viewDidLoad() {
let appDelegate = UIApplication.sharedApplication().delegate as!AppDelegate
self.layerClient = appDelegate.layerClient
self.conversationListViewController = ConversationListViewController(layerClient: appDelegate.layerClient)
self.conversationListViewController.displaysAvatarItem = true
self.navigationController!.pushViewController(self.conversationListViewController, animated: true)
}
}
But this is not working. And giving this kind of effect: the ConversationViewController is not loaded in UINavigationController. I am not sure if I am doing it the correct way. I'm searching for the correct way, but unable to find.
I Solved it. I dragged new NavigationViewController and added ConversationListViewController to rootviewController.I think i should try this first. Anyways thanks guys for your help.
Because you want to do this programatically:
You need to manually initialize the controller before stacking it up on the Navigation Controller. Try this:
navigationController?.pushViewController(self.conversationListViewController.init(), animated: true)

adding UIPageViewController to a view controller's container view

I'm trying to Add my pageViewController to a container view on my main viewController . For that , I have added these codes
addChildViewController(pageViewController!)
self.sliderView.addSubview(pageViewController!.view)
pageViewController!.didMoveToParentViewController(self)
But when I run the app ,it's looks like this :
http://i.stack.imgur.com/0Sf17.jpg
I want to add my pageViewController in the yellow containerView which name is sliderView .
What's wrong with that?
Thanks
Please provide more code as the given example code works pretty well.
Possible causes could be the forced unwrap of your pageViewController. Additionally ensure that the controller is properly instantiated from Storyboard like
guard let vc = storyboard?.instantiateViewControllerWithIdentifier("YourViewControllerID") as? YourViewControllerClass else
{
return
}
sliderView.addSubview(vc.view)
vc.didMoveToParentViewController(self)
You can set YourViewControllerID directly within the Storyboards Identity Inspector

IBOutlet link to embedded container view controller

I have a complex iPad view that I manage by having several view controllers. I previously (before iOS6/Xcode 4.5) did this by allocating my view controllers in code, and hooked up the various views to them though links to the master view.
What I would like to do is use the new UIContainerView container views to embed the view controllers in the storyboard file. I don't seem to be able to make an IBOutlet link to the embedded view controller to the master controller.
Is it possible to do this? Or to retrieve the embedded controller via a tag or something in the code?
This question is SPECIFICALLY about using container views
Another option for some cases is to capture the embedded controller using -prepareForSegue:sender:.
For example, if I have a UINavigationController embedded within a CustomContainerViewController, I can name the embed segue embedContentStack in the storyboard and capture it in CustomContainerViewController via
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"embedContentStack"]) {
// can't assign the view controller from an embed segue via the storyboard, so capture here
_contentStack = (UINavigationController *)segue.destinationViewController;
}
}
I'm not sure what you mean by "retrieve the embedded controller". When you want to use a controller you use the UIStoryboard method instantiateViewControllerWithIdentifier:, using the identifier that you give to the controller in IB. You can also use the performSegueWithIdentifier:sender: method (which also instantiated the view controller). You should check out the "Using View Controllers in Your App" section in the Apple docs. It also makes reference to the fact that child view controllers are instantiated at the same time as the container controller.
After edit: If you embed a container view in another view controller, that embedded view's controller can be referenced from the containing controller with self.childViewControllers (which will be an array, so if there is just one, you can get it with lastObject).
Here is another thread about it: Access Container View Controller from Parent iOS
They propose to keep a reference in prepareForSegue or search for the embedded viewController in self.childViewControllers
Note of Caution
Before proceeding to use an answer to this question, you may wish to reflect whether the embedded things really need to be view controllers.
Eg, if you're embedding a UICollectionViewController subclass, could you instead embed a UICollectionView subclass? Or, even better, could you embed a UIView subclass that hides away the UICollectionView behind a simple ViewModel?
In the code base I'm currently working on, I'm embedding two view controllers in to another view controller. Both could fairly easily be plain views instead, and could then be more easily bound to in the storyboard, without this messy code.
Unfortunately, they are currently view controllers and I'm not in a position to simplify them in to plain views right now, so this will have to do.
Background
I'm using the approach of picking up the embed segue in prepare(for segue:, sender:) as suggested by Playful Geek here.
I wanted to show the swift I'm using for this, as it seems to be fairly tidy…
class EditionLandingViewController: UIViewController {
fileprivate var titlesView: SectionTitlesViewController!
fileprivate var sectionsView: SectionsViewController!
}
//MARK:-
extension EditionLandingViewController {
private enum SegueId: String {
case embedTitles
case embedSections
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
super.prepare(for: segue, sender: sender)
guard
let segueRawId = segue.identifier,
let segueId = SegueId(rawValue: segueRawId)
else { return }
switch segueId {
case .embedTitles:
self.titlesView = segue.destination as! SectionTitlesViewController
case .embedSections:
self.sectionsView = segue.destination as! SectionsViewController
}
}
}
Discussion
I've chosen to name segues as action methods.
Using an enum cases for segue identifiers means you've got the compiler and tooling on your side, so its much harder to get a segue name wrong.
Keeping the segue ids in a private enum within the extension scope seems appropriate in this case as these segues are not needed anywhere else (they can't be performed, for example).
I'm using implicitly unwrapped types for the embedded view controllers because (in my case anyway) it's a logic error if they are missing.
Similarly, I'm also happy to force cast the destination view controller types. Again, it would be a logic error if these types are not the same.
Swift version of the top-voted Answer. Years later, Interface Builder still does not seem to support dragging IBOutlets to embedded Container Views.
Instead, set the outlets in prepare(for:sender:):
#IBOutlet var someViewController: SomeViewController!
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "EmbedSomeViewController", let destination = segue.destination as? SomeViewController {
someViewController = destination
}
}
You must also set up the UIContainerView on your Storyboard. Xcode will generate an embed segue automatically; set the segue's Identifier.

Resources