Is it possible on iPhone via UISplitViewController to return from the master controller to the detail one? I have tried in master changing displayMode to PrimaryHidden, using showDetailViewController with splitViewController?.viewControllers[0], but nothing was able to show back the detail controller.
I would like to have both controllers without dismissing and reloading, because one includes a map and the second one preferences of map objects.
Lets say you have a button in the master view which when pressed will take you to detail view. Here is an example how that would go
#IBAction func buttonToGoToDetailView(sender: UIButton) {
performSegueWithIdentifier("segue id in storyboard", sender: nil)
}
// prpare for segua to detail view
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let destination = segue.destinationViewController as? UIViewController
if let dvc = destination as? NameOfTheDetailViewController{
if segue.identifier = "segue id in storyboard" {
//use dvc to pass data to the detail if there is any
}
}
}
Related
I have a view controller with a container view that has a tab bar controller embedded in it. Im using this to display 3 different view controllers based on what is pressed from a segmented control in the main vc. I have been following this solution: https://stackoverflow.com/a/38283669/11536234
My problem is that when I change the segmented control index (by pressing a different segment) I can't figure out how to "reach" the prepare function.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
print("prepare reached")
//super.prepare(for: segue, sender: sender)
//switch(segue.identifier ?? "") {
//case "TabBar":
guard let TabController = segue.destination as? UITabBarController else {
fatalError("Unexpected destination: \(segue.destination)")
}
TabController.selectedIndex = toggle.selectedSegmentIndex
//default:
//fatalError("Unexpected Segue Identifier; \(segue.identifier)")
//}
}
#IBAction func toggleAction(_ sender: UISegmentedControl) {
print("toggle is now at index: ", toggle.selectedSegmentIndex)
//performSegue(withIdentifier: "TabBar", sender: sender)
//container.bringSubview(toFront: views[sender.selectedSegmentIndex])
}
So far i have tried placing a performsegue function in an action function linked to the segmented control. This doesn't work, however, because it essentially adds another embedded tab bar programmatically or calls the embed segue again and I receive this error statement: "There are unexpected subviews in the container view. Perhaps the embed segue has already fired once or a subview was added programmatically?"
*The commented lines of code are there to show what I've tried that hasn't worked vs where I'm at.
When you embed a view controller to a container view from another view controller(MainVC), the segue is performed only once when MainVC loads. To pass values to the embedded UIViewController/UITabBarController, you need to get the child view controller and send the data
class MainVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func segmentControlAction(_ sender: UISegmentedControl) {
if let tabBarVC = self.children.first(where: { $0 is UITabBarController }) as? UITabBarController {
tabBarVC.selectedIndex = sender.selectedSegmentIndex
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
//called before mainvc viewDidLoad
let destinationVC = segue.destination as? UITabBarController
destinationVC?.selectedIndex = 1
}
}
You can't do what you are trying to do.
With embed segues the segue fires when the host view controller is first loads. That invokes your prepare(for:sender) method, once and only once, before the embedded view controller's views are loaded. It doesn't get called again.
What you need to do is to save a pointer to your child view controller in an instance variable. Define a protocol that the parent uses to talk to the child, and then use that protocol to send a message to the child when the user selects a different segment in your segmented control.
Then the child (presumably the tab bar controller) can switch selected tabs in response to the message you define.
I am trying to do something this:
I want to pass some data to ApplicationsViewController which is embedded in nav bar, therefore I get the error: Could not cast value of type 'UINavigationController'
I am not able to understand how to implement the same. Help is much appreciated. Thank you.
The reason is you can't pass data directly to ApplicationViewController as InboxViewController segue's destination is UINavigationController.
So, first you need to access UINavigationController and after that ApplicationsViewController from the stack.
Try the code below:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToApplications" {
if let navigation = segue.destination as? UINavigationController, let applicationVC = navigation.topViewController as? ApplicationsViewController {
applicationVC.id = "RGB"
}
}
}
when pass data application view controller which is rootviewController of UINavigationController. you should give segue name of navigation controler and type cast as UINavigationController as destination viewcontroller.
Fetch rootviewController which is application View controller and assign value of id
Here is code how to assign value to Application ViewController
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
if segue.identifier == "navigationSegue" { // segue of navigationVC
let navVc = segue.destination as! UINavigationController
let appVc = navVc.viewControllers.first as! ApplicationsViewController
appvc.id = "RGB"
}
}
I want to create a segue to pass data to another view controller but there are certain criteria that must happen for the segue to happen. If possible i would prefer to use the segue Id instead of the dragging method.
this is an example Im trying to accomplish
#IBAction func SubmitButtonPressed(sender: AnyObject) {
if 1<0 {
// dont perform segue
}else{
//Perform segue
// i want to pass this data in the next VC
var data = "foo"
//this is my segue id i want o use to go to the Second VC
var segueId = "segueForgotPasswordTwo"
// second VC
var secondVc = "viewController2"
// Iwant to to use prepare for segue but im getting errors in the parameters
prepareForSegue(UIStoryboardSegue, sender: AnyObject?){
}
}
}
Your question is a bit unclear but I believe this is what you are looking for...
func someFunction(){
if //some condition {
//code
}else if //some condition {
//code
} else {
//perform segue by using the folowing line. Assign the identifier to the segue in the storyboard.
//Do this by first creating a segue by dragging from a view controller to the destination view controller. Be sure to drag from the VIEWCONTROLLER, to the destination VIEWCONTROLLER. DO NOT just drag from the button. Next, choose the type of segue (eg. show or present modally), and then type in an indentifier for this segue.
performSegueWithIdentifier("SegueIdentifier", sender: nil)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "SegueIdentifier" {
//now find your view controller that you are seguing to.
let controller = segue.destinationViewController as! SomeViewController
//access the properties of your viewController and set them as desired. this is how you will pass data along
controller.property = someValue
}
}
Overview:
Hook the segue from the source view controller to the destination view controller (see left side red arrows)
Don’t hook it from the button to the destination view controller
Create an action for the button to do your custom condition check then perform segue
Screenshot:
Code:
var data = "foo"
#IBAction func buttonPressed(sender: UIButton) {
let someCondition = true
if someCondition {
performSegueWithIdentifier("showGreen", sender: self)
}
else {
performSegueWithIdentifier("showPink", sender: self)
}
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showGreen" {
let greenVC = segue.destinationViewController as! GreenViewController
// Make sure the data variable exists in GreenViewController
greenVC.data = data
}
}
You can implement the shouldPerformSegueWithIdentifier function in your ViewController. When the segue is triggered, this function can cancel the segue if it returns false, so you can simply include whatever logic is required in this function and return true/false as appropriate.
I am using for the first time the Unwind Segue approach. I have multiple view controllers as can be seen in the picture below (a few of them shown of course). In the Edit Profile I have a Done button. Once clicked I trigger an IBAction that triggers an unwind segue.
Here is the code for the Done button in the nav bar:
#IBAction func unwindToMainViews(sender: UIStoryboardSegue) {
//let sourceViewController = sender.sourceViewController
self.performSegueWithIdentifier("unwindToMainSegue", sender: self)
}
and in the
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!)
I am doing the following to pass data from Edit Profile back to Home View
if (segue.identifier == "unwindToMainSegue") {
// pass data to next view
let tabCtrl = segue.destinationViewController as! UITabBarController
let destinationVC = tabCtrl.viewControllers![0] as! HomeViewController
destinationVC.userObject = self.userObject;
}
When segue identifier is matched and code is executed (to transfer userObject from this controller to another), it triggers the error:
Could not cast value of type 'app.EditProfileViewController' (0x100b99d80) to 'UITabBarController' (0x104a1d030).
How can this error be fixed? I am surprised since i am casting to UITabBarController so thought it should work.
You don't return to the UITabBarController in an unwind segue. You return to the ViewController that triggered the original segue, or one if its ancestors.
As #jlehr stated in the comments:
Unwind segues don't return to anything; they dismiss any pushed and
presented view controllers between the source and destination view
controller. The destination is wherever the implementation of the
unwind method is found, regardless of how the source view controller
was presented.
To unwind to the viewController that triggered the original segue, you need to implement the #IBAction func returnToHere(segue: UIStoryboardSegue) function in the viewController you want to return to.
Then when you set up your Done button by dragging to the Exit icon, you select returnToHere from the pop-up.
To pass data back to the sourceViewController, give your unwind segue an identifier such as "unwindToSource", then override prepareForSegue in the viewController you are returning from:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "unwindToSource" {
let dvc = segue.destinationViewController as! SourceViewController
dvc.userObject = self.userObject
}
}
I have to write an iOS app that supports both iOS 7 and 8 and in this app I have two view controllers A and B with navigation controllers and a segue between them. When the segue activates, I have to fetch data from the view controller A to the view controller B. My code works perfectly on iOS 8 but not on iOS 7.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
if segue.identifier == userDataSegue {
let navController = segue.destinationViewController as? UINavigationController
if let userDataTableViewController = navController?.topViewController as? UserDataTableViewController {
userDataTableViewController.userData = user
}
}
}
Do you know why does this happen and how can I fix it? I could "work around" the problem by saving stuff in NSUserDefaults and reading it in the vc B but that would make my code a mess.
I appreciate any help :D
Don't forget to create a public property userData in Second ViewController.
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!)
{
if (segue.identifier == "segueTest") {
var svc = segue!.destinationViewController as secondViewController;
svc.userData = user
}
}