I am trying to pass data from a tableview cell into a tab view controller to be used by the tab view controller's corresponding views. However the overriden func prepare method below is not being called and the program goes to the tab view controller bypassing this method totally.
Storyboard showing the views
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let selectedCarIndex = self.savedCarsTableVC.indexPathForSelectedRow?.row
let destVC = segue.destination as! TabBarController
destVC.selectedCar = savedCars[selectedCarIndex!]
}
I am expecting the selectedCar object to return data from the array however it's nil.
I would try setting the selectedCarIndex in tableView didSelectRow method. Also, make sure you want to be navigating to TabBarController and not some ViewController embedded in the TabBar.
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: IndexPath) {
self.performSegue(withIdentifier: "youridentifier", sender: indexPath)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let selectedCarIndex = sender as! IndexPath
let destVC = segue.destination as! TabBarController //Are you sure this is the correct ViewController to be casting to?
destVC.selectedCar = savedCars[selectedCarIndex.row]
}
Related
I have the following portion of my code that I'm trying to work out in order to move from a table view controller to a view controller.
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
let donation = donations[indexPath.row]
print(donation)
self.performSegue(withIdentifier: "showDonationReviewForm", sender: Any?)
}
On the above, when I print donation, it correctly prints the object and it's related fields. I know at some point I would need to use override func prepare(for segue... but I don't know how I am passing along the donation object to the next controller.
You can try
performSegue(withIdentifier: "showDonationReviewForm", sender:donations[indexPath.row])
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showDonationReviewForm" {
if let nextViewController = segue.destination as? NextViewController {
nextViewController.toSend = sender as! Donation
}
}
}
class NextViewController :UIViewController {
var toSend:Donation?
....
}
Assuming donations is an array of Donation model
I'm trying to push data from one viewController to another. I've connected a viewController to another ViewController's navigationController and then set the identifier to "showItemSegue". I get an error in these two lines:
var detailController = segue.destinationViewController as ShowItemViewController
detailController.currentId = nextId!
Image illustration:
The code:
override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
nextId = itemArray?.objectAtIndex(indexPath.row).objectForKey("objectId") as? NSString
self.performSegueWithIdentifier("showItemSegue", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
if (segue.identifier == "showItemSegue") {
var detailController = segue.destinationViewController as ShowItemViewController
detailController.currentId = nextId!
}
}
The destination view controller of the segue is the UINavigationController. You need to ask it for its top view controller to get to the real destination view controller:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showItemSegue" {
let navController = segue.destination as! UINavigationController
let detailController = navController.topViewController as! ShowItemViewController
detailController.currentId = nextId!
}
}
I have two ViewControllers in the first I created a tableView where I can insert just a text into a cell.
In the SecondViewController I also have a tableView with the same function, bu HOW can I make it that when I click a cell in the first tableView, I can get into a separate SecondTableView (Array).
So I'm this far, but I think the categorize function must be in the didSelectRowAt, when I click a Row.
FirstViewController:
todos: This is a String Array (I want this as the Category)
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "hhh"{
//let destination = segue.destination as? UINavigationController
let vc = segue.destination as? SecondViewController
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "SecondViewController") as? SecondViewController
//label name
vc?.name = todos[indexPath.row]
self.present(vc!, animated: true, completion: nil)
tableView.deselectRow(at: indexPath, animated: true)
self.performSegue(withIdentifier: "hhh", sender: indexPath)
let indexpath = todos[indexPath.row]
print("indexpath:\(indexpath)")
print("row: \(indexPath.row)")
}
}
In the SecondViewController I have a SecondArray=[String]() these are actually the Todos.
On both ViewControllers I can insert a cell with text but don't know how to pass the data back:=?
In the comments I suggested using a UISplitViewController, as this works well with any kind of master/detail type of app. (In fact, it's an Xcode project type.)
But in case you require using a UINavigationController, here's what I to to "toggle" between two views this way:
FirstViewController:
#IBAction func showFrameVC() {
updateMaskImage()
self.performSegue(withIdentifier: "ShowSecondView", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "ShowSecondView" {
if let vc = segue.destination as? FrameViewController {
vc.someValue = someValue
vc.firstVC = self
}
}
}
Basically, pass the instance of the first view controller along with any data you need to pass.
SecondViewController:
var someValue:String!
weak var subjectVC:FirstViewController!
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if isMovingFromParentViewController {
firstVC.someValue = someValue
}
}
Here you let the navigation controller do it's thing, which is pop the second view controller off the stack after passing back the data it changed. Since you are maintaining a weak value of the first view controller, you free up that memory when the second controller is released.
In your code, you are presenting your SecondViewController in 2 ways in same function.
self.present(vc!, animated: true, completion: nil)
and
self.performSegue(withIdentifier: "hhh", sender: indexPath)
intention of both lines are same, But 2 way of implementation.
if my thinking is right you don't have to perform segue (second line of code mentioned above and also No prepare for segue method).
I want to move from one view controller to another and send userId:
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
self.performSegueWithIdentifier("chosenPerson", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destinationViewController as? chosenPersonViewController
let indexPaths = self.collectionView!.indexPathsForSelectedItems()!
let indexPath = indexPaths[0] as NSIndexPath
chosenPerson!.userID = self.usersArray[indexPath.row].userId
}
by clicking I get: "fatal error: unexpectedly found nil while unwrapping an Optional value"
what I do wrong?
If you have given segue in StoryBoard DON'T Call this self.performSegueWithIdentifier("chosenPerson", sender: self) method in didSelectItem
If you have given segue in storyboard override func prepareForSegue - this method calls first after that didSelectItem calls
Please refer storyBoard once (below Image for Sample)
I think problem is in self.usersArray[indexPath.row].userId May this returns nil
Swift2:
self.performSegueWithIdentifier("chosenPerson", sender: self)
Swift3:
self.performSegue(withIdentifier: "chosenPerson", sender: self)
Swift2:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destinationViewController as? chosenPersonViewController
let indexPaths = self.collectionView!.indexPathsForSelectedItems()!
let indexPath = indexPaths[0] as NSIndexPath
chosenPerson!.userID = self.usersArray[indexPath.row].userId //May it found nil please re - check array values
}
Swift3:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destination as! chosenPersonViewController
if let indexPath = collectionView.indexPathForSelectedItem {
chosenPerson!.userID = self.usersArray[indexPath.row].userId //May it found nil please re - check array values
}
}
}
When performing the segue, pass the indexPath as the sender and try using this switch statement. If you see "unknown segue" printed out when you select a cell, the destination controller is not of type chosenPersonViewController.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("chosenPerson", sender: indexPath)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
switch (segue.destinationViewController, sender) {
case (let controller as chosenPersonViewController, let indexPath as NSIndexPath):
controller.userID = usersArray[indexPath.row].userId
default:
print("unknown segue")
break
}
}
One possible issue could be that in your storyboard you have not set the identifier for your segue to be "chosenPerson". To fix this first make sure you have a segue between your first and second view controllers, which can be created by control dragging one from one view controller to another.
Then make sure the segue has an identifier, specifically: "chosenPerson". To do this: click on the segue between the first two view controllers, then navigate to the attributes tab, and then set the identifier box to be "chosenPerson". Save the storyboard with your changes and now you should be able to call prepareForSegue with that identifier and not experience a fatal error.
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
self.selectedClubState = stateNamesForDisplay[indexPath.row]
self.performSegueWithIdentifier ("Cities", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var clubsToPassToCitiesViewController = [clubObject]()
if segue.identifier == "Cities" {
for club in clubsForTable{
if club.clubState == self.selectedClubState{
clubsToPassToCitiesViewController.append(club)
}
}
let citiesView = segue.destinationViewController as? citiesViewController
citiesView?.clubsForChosenCity = clubsToPassToCitiesViewController
}
}
Segue is being executed twice leading to the next VC. How can I prevent this from happening?
Delete the current segue in storyboard. Then CTRL-drag from the viewController (not the cell) to the next view controller and name it "Cities". Now, when you select a cell, the didSelectRowAtIndexPath() will fire first and will call performSegueWithIdentifier()
However, if all you're looking to do in the didSelectRowAtIndexPath() is get the row that performed the segue, you can maintain your original setup of having the cell segue from the storyboard, remove didSelectRowAtIndexPath() and in prepareForSegue() do:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let indexPath = self.tableView.indexPathForSelectedRow {
self.selectedClubState = stateNamesForDisplay[indexPath.row]
}
var clubsToPassToCitiesViewController = [clubObject]()
if segue.identifier == "Cities" {
for club in clubsForTable{
if club.clubState == self.selectedClubState{
clubsToPassToCitiesViewController.append(club)
}
}
let citiesView = segue.destinationViewController as? citiesViewController
citiesView?.clubsForChosenCity = clubsToPassToCitiesViewController
}
}
You are the one executing the segue twice — once automatically in the storyboard (because your segue emanates as an Action Segue from the cell prototype), and once in code when you say self.performSegueWithIdentifier. If you don't want the segue executed twice, remove one of those.
Personally, my recommendation is that you delete didSelectRow entirely and move your self.selectedClubState assignment into prepareForSegue.