Im trying to use performSegueWithIdentifier when user taps in a row of a table view. How ever, it doesn't work and i have the next error:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not perform segue with identifier 'categoriesS'. A segue must either have a performHandler or it must override -perform.'
I googled the error, but i don't find anything. I've already create the push segues in the storyboard and set them the identifiers that I use in my code.
This is my code(PD: Im using this tableview, as a side bar menu):
import Foundation
class menuVC: UIViewController,UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var ProfileImage: UIImageView!
#IBOutlet weak var myTable: UITableView!
var opciones = [String]()
var segues = [String]()
override func viewDidLoad() {
super.viewDidLoad()
myTable.delegate = self
opciones = ["Categories","My Coins","Get Coins","Share","LogOff","Exit"]
segues = ["categoriesS","myCoinsS","getCoinsS"]
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 6
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
print(opciones[indexPath.row])
self.performSegueWithIdentifier(segues[indexPath.row], sender: self)
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as UITableViewCell
cell.textLabel?.text = opciones[indexPath.row]
return cell
}
}
Thanks!
You have given a wrong segue as console clearly stated that. You are looking for 'categoriesS' which is in 'segue' array, but you are passing from 'opciones' array. Look closely.
Edit
I saw your edit, looks like u have populate your table using different array, but u have used other array in didselectrow.please check it
Related
Edit: mentioned at the bottom I was using another stackoverflow question for guidance. Turns out its the same issue that I don't believe ever got solved after the person edited their question. So I copied the exact same issue into my code: How to know which cell was tapped in tableView using Swift
There's probably many things wrong with my code at this point, but the main issue is the very edit at the bottom of the post this author puts on his question. I know that makes this a duplicate then but no one has answered that. All the accepted answers have the same outcome as my issue.
I'm very new to swift and I'm creating a flashcard type app where tapping on a tableview cell for details shows a term and definition. These terms and definitions are stored in two parallel arrays and the index is supposed to be the indexPath.row.
My issue is that int selectedCell which should be the index of the array for whichever cell the user taps always runs the code to display the term and definition before running the code to find the selected cell.
My earlier error before this was that if I made selected cell an optional (var selectedCell: Int?), the program would crash because its nil. To fix that, I made it var selectedCell: Int = 0 and that worked until I realized that no matter what I tap, the first selectedCell will always be 0.
How can I get the selectedCell before the terms and definitions are displayed.
This is the code inside CardViewController, the controller brought up after the user touches a cell for details. There are only two labels (term and definition) so the code is pretty scarce here.
override func viewDidLoad() {
super.viewDidLoad()
// Testing
print("new selectedCell: \(selectedCell)")
// Update labels for term and definition
termLabel.text = "Term: \n" + cards[selectedCell]
definitionLabel.text = "Definition: \n" + details[selectedCell]
}
The code inside CardTableViewController where the very last override func is what gives me the selectedCell. I have checked that the number is correct when tapped, it just runs after cardviewcontroller apparently.
This is the code for CardTableViewController, where it is tableview cells of each term from the flashcard listed.
Not to be confused with CardViewController which is the little detail flashcard screen that pops up
import UIKit
var cards = [String]()
var details = [String]()
var newCard:String = ""
var newDetail:String = ""
var study = [String]()
var selectedCell: Int = 0
class CardTableViewController: UITableViewController {
#IBOutlet var createCardButton: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cards.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cardCell", for: indexPath)
cell.textLabel?.text = cards[indexPath.row]
return cell
}
#IBAction func cancel(segue:UIStoryboardSegue) {
}
#IBAction func create(segue:UIStoryboardSegue) {
let addCard = segue.source as! AddCardViewController
newCard = addCard.term
newDetail = addCard.definition
print("term: \(addCard.term)")
print("definition: \(addCard.definition)")
cards.append(newCard)
details.append(newDetail)
study.append(newCard)
tableView.reloadData()
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
selectedCell = indexPath.row
print("selectedCell: ", selectedCell)
}
}
I know it's out of order because of the print statements I put in. Instead, selectedCell should print before new selectedCell. Notice how new selectedCell will be 0 due to initialization (nil if I didn't initialize it) and then is always lagging one cell touch behind what it should be?
the segues for cancel and create are bar button items on the (details of the flashcard screen). They are unwind segues that I followed some online tutorial on for how to create an text field and unwind.
for background on the addCardViewController and unwind segues, this is the code inside that:
class AddCardViewController: UIViewController {
#IBOutlet weak var cardTerm: UITextField!
#IBOutlet weak var cardDefinition: UITextField!
var term:String = ""
var definition:String = ""
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "createSegue" {
term = cardTerm.text!
definition = cardDefinition.text!
}
}
Here's the printing results for the cell indexes
new selectedCell: 0
selectedCell: 0
new selectedCell: 0
selectedCell: 1
new selectedCell: 1
selectedCell: 1
Honestly not sure if there's a way to call that function first or if I'm choosing the selectedCell wrong (I got the idea off another post on stack overflow: How to know which cell was tapped in tableView using Swift)
Storyboard for my app. Shows the list of cards tableview controller and the card view controller:
So in my storyboard, I set up two ViewControllers (CardsTableViewController and CardViewController)
The segue in between these two view controllers is called CardSegue and is set up to present modally.
The reuse identifier for the prototype UITableViewCell in CardsTableViewController is CardCell.
This is how the CardsTableViewController looks like:
import UIKit
struct Card {
let term: String
let definition: String
}
class CardsTableViewController: UITableViewController {
var selectedCell: Int = 0
let cards: [Card] = [Card(term: "Привет", definition: "Hello"), Card(term: "Да", definition: "Yes")]
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cards.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CardCell", for: indexPath)
cell.textLabel?.text = cards[indexPath.row].term
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
selectedCell = indexPath.row
performSegue(withIdentifier: "CardSegue", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let vc = segue.destination as? CardViewController {
let selectedCard = cards[selectedCell]
vc.card = selectedCard
vc.selectedCell = selectedCell
}
}
}
This is the CardViewController:
import UIKit
class CardViewController: UIViewController {
var card: Card = Card(term: "<Set me>", definition: "<Set me>")
var selectedCell: Int = 0
#IBOutlet weak var termLabel: UILabel!
#IBOutlet weak var definitionLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Testing
print("new selectedCell: \(selectedCell)")
termLabel.text = "Term: \n" + card.term
definitionLabel.text = "Definition: \n" + card.definition
}
}
I created a Card struct which has a term and a definition, both being Strings.
I created an array of two Cards with two Russian words. This is the data we're working with.
In didSelectRowAt indexPath, I have set up the same setting of "selectedCell", which is defined at the top.
Directly after, I call performSegue, which will send the user to the CardViewController, which will display the term and the definition.
The prepare(for segue) method is always called whenever performSegue is called. In the view controller, if you start typing..."prepare(for...." Xcode will probably fill it out for you.
In this method, I get the selected card, and I pass the card to the CardViewController. In this example, I pass selectedCell, but I don't know if it's really necessary, it depends on what you are trying to achieve, I guess.
This is how the two view controllers should be communicating.
Here's some good information about how to pass information from one view controller to the next: See this section: Passing Data Between View Controllers Using Segues
I've already looked at the post UITableView.reloadData() is not working. I'm not sure that it applies to my situation, but let me know if I'm wrong.
My app has a tableView. From the main viewController I am opening another viewController, creating a new object, and then passing that object back to the original viewController, where it is added to an array called timers. All of that is working fine. However, when I call tableView.reloadData() in didUnwindFromNewTimerVC() to display the updated contents of the timers array, nothing happens.
NOTE: I have verified that the timers array is updated with the new object. Its count increments, and I can access its members. Everything else in didUnwindFromNewTimerVC() executes normally. The tableView just isn't updating to reflect it.
Here is my code:
import UIKit
class TimerListScreen: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tabelView: UITableView!
var timers = [Timer]()
let tableView = UITableView()
override func viewDidLoad() {
super.viewDidLoad()
tabelView.delegate = self
tabelView.dataSource = self
let tempTimer = Timer(timerLabel: "temp timer")
timers.append(tempTimer)
}
#IBAction func didUnwindFromNewTimerVC(_sender:UIStoryboardSegue){
guard let newTimerVC = _sender.source as? newTimerVC else{return}
newTimerVC.timer.setTimerLabel(timerLabel: newTimerVC.timerLabel.text!)
timers.append(newTimerVC.timer)
tableView.reloadData()
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tabelView.dequeueReusableCell(withIdentifier: "TimerCell", for: indexPath) as? TimerCell{
let timer = timers[indexPath.row]
cell.updateUI(Timer: timer)
return cell
}else{
return UITableViewCell()
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return timers.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 78
}
}
Thank you
Please note the spelling. There are two table view instances: the outlet tabelView and a (pointless) instance tableView.
Reload the data of the outlet
tabelView.reloadData()
and delete the declaration line of the second instance let tableView ....
However I'd recommend to rename the outlet to correctly spelled tableView (you might need to reconnect the outlet in Interface Builder).
And force unwrap the cell
let cell = tabelView.dequeueReusableCell(withIdentifier: "TimerCell", for: indexPath) as! TimerCell
and remove the if - else part. The code must not crash if everything is hooked up correctly in IB.
I know this particular question has been asked and answered previously in SO but cross checked those answers and still not able to fix this issue. Can be a silly mistake but unable to nail it.
Cross checked :
Cell Identifierid
datasource and delegate added through Interface builder
Code :
var sensorFields = [Sensor]()
override func viewDidLoad() {
super.viewDidLoad()
readParseDataFromCSV(file: "csvFile")
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print(self.sensorFields.count)// has count 120
return self.sensorFields.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SensorTableCell") as! SensorTableViewCell
cell.lblSensorName.text = sensorFields[indexPath.row].labelName
cell.lblSensorValue.text = sensorFields[indexPath.row].labelValue
print(sensorFields[indexPath.row].labelName) // doesn't seem to enter to this code block
print(sensorFields[indexPath.row].labelValue)
return cell
}
func readParseDataFromCSV(file:String){
let filepath = Bundle.main.path(forResource: file, ofType: "csv")!
do {
let csv = try CSV(contentsOfURL: filepath)
let rows = csv.rows
for row in rows{
let sensorlblName = row["data column 1"]
let sensorlblValue = row["data column 2"]
let sensor = Sensor(labelName: sensorlblName!, labelValue: sensorlblValue!)
sensorFields.append(sensor)
}
} catch {
print(error.localizedDescription)
}
}
class SensorTableViewCell: UITableViewCell {
#IBOutlet weak var lblSensorName: UILabel!
#IBOutlet weak var lblSensorValue: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
Is there anything missed out , using other tableviews in the app already which is working perfectly apart from this one.
Using Xcode 8.1 and Swift 3.0
Edit :
Added reloadData()
Seems like
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {}
is not firing too.
Please help.
Thanks in advance.
Just appending data to your sensorFields array has no impact on the cells displayed in your tableView.
You need to call reloadData on the tableView so it knows the data did change and repopulates the cells with the new data.
for row in rows {
let sensorlblName = row["data column 1"]
let sensorlblValue = row["data column 2"]
let sensor = Sensor(labelName: sensorlblName!, labelValue: sensorlblValue!)
sensorFields.append(sensor)
}
tableView.reloadData()
I would also prefer
// newer dequeue method guarantees a cell is returned and resized properly, assuming identifier is registered
// Swift 2
func dequeueReusableCellWithIdentifier(identifier: String, forIndexPath indexPath: NSIndexPath) -> UITableViewCell
// Swift 3
func dequeueReusableCell(withIdentifier identifier: String, for indexPath: IndexPath) -> UITableViewCell
to
// Used by the delegate to acquire an already allocated cell, in lieu of allocating a new one.
// Swift 2
func dequeueReusableCellWithIdentifier(identifier: String) -> UITableViewCell?
// Swift 3
func dequeueReusableCell(withIdentifier identifier: String) -> UITableViewCell?
because dequeueReusableCellWithIdentifier(identifier: String) does not guarantee returning a UITableViewCell when the cell with identifier was not yet allocated. ("[...] acquire an already allocated cell, in lieu of allocating a new one.")
And make sure your IBOutlets are connected! (lblSensorName and lblSensorValue)
check this
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
var cell = tableView.dequeueReusableCellWithIdentifier("SensorTableCell") as UITableViewCell!
if !cell {
cell = UITableViewCell(style:.Default, reuseIdentifier: "SensorTableCell")
}
}
Why I get this error?
Terminating app due to uncaught exception
'NSInternalInconsistencyException', reason: '-[UITableViewController
loadView] loaded the "pB1-re-lu8-view-o7U-YG-E7m" nib but didn't get a
UITableView.'
here is my code:
class FriendListTableViewController: UITableViewController{
var objects = NSMutableArray()
var dataArray = [["firstName":"Debasis","lastName":"Das"],["firstName":"John","lastName":"Doe"],["firstName":"Jane","lastName":"Doe"],["firstName":"Mary","lastName":"Jane"]]
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dataArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
let object = dataArray[indexPath.row] as NSDictionary
(cell.contentView.viewWithTag(10) as! UILabel).text = object["firstName"] as? String
(cell.contentView.viewWithTag(11) as! UILabel).text = object["lastName"] as? String
return cell
}
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return false
}
my storyboard is like this:
I have face same issue once upon time, and So stupid mistake it was, I have subclass the UITableViewController, where I have added UITableView in UIViewController
From your storyboard Image, it may be solved if you use UIViewController instead of UITableViewController, Just try that way can solve your issue,like
class FriendListTableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate
SWIFT 2 UPDATE
I tried #Viralsavaj's answer but it didn't work for me until I "hooked up" the tableView as an outlet from the storyboard in the ViewController.
like this: #IBOutlet weak var tableView: UITableView!
Also add this to your class as #Viralsavaj mentioned:
class TableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate
I used specifically this link help as well: How to reference tableView from a view controller during a segue
Just drag your tableView into the ViewController and make it an outlet. Then you can reference its properties such as self.tableView.reloadData().
This property as well as others that referenced the tableView were giving me errors until I added the tableView as a referencing outlet.
Hope this helps those in the future.
I had this issue with Swift 2, Xcode 7.2, I changed a View Controller I dragged to my Storyboard to a custom UITableViewController class, I then dragged a Table View onto the View Controller. I didn't realize I placed it as a child of the View that was part of the original View Controller I dragged onto the Storyboard.
I simply deleted the View and added the Table View again as the first child of the Super View.
I'm having trouble creating custom table view cells in swift with Xcode6 (beta 4). More precisely I'm unable to access (unwrap) my custom UILabels inside the cell, since they never gets initialized.
Here's how I've got it all setup:
I've made a view in storyboard, which contains a table view with a prototype cell:
The view is hooked up to a class MyCoursesTableViewController, and the cell (with identifier courseCell) to CourseTableViewCell. I've pasted both classes below (with just the relevant bits of code):
MyCoursesTableViewController.swift
import UIKit
class MyCoursesTableViewController: NavToggleTableViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.registerClass(CourseTableViewCell.self, forCellReuseIdentifier: "courseCell")
}
override func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
return 1
}
override func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
return 1
}
override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
var cell : CourseTableViewCell = tableView.dequeueReusableCellWithIdentifier("courseCell", forIndexPath: indexPath) as CourseTableViewCell
// cell is not nil
if let titleLabel = cell.titleLabel {
// never gets here
} else {
cell.textLabel.text = "Course Title"
}
return cell
}
}
The NavToggleTableViewController class is just a common baseclass I use for all view controllers and doesn't affect the result.
CourseTableViewCell.swift
import UIKit
class CourseTableViewCell: UITableViewCell {
#IBOutlet weak var courseIcon: UIImageView!
#IBOutlet weak var teacherIcon: UIImageView!
#IBOutlet weak var studentsCountIcon: UIImageView!
#IBOutlet weak var titleLabel: UILabel!
#IBOutlet weak var studentsCountLabel: UILabel!
#IBOutlet weak var teacherLabel: UILabel!
init(style: UITableViewCellStyle, reuseIdentifier: String!) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
}
Below is a picture of how I've configured the cell in the utilities pane (in storyboard):
The problem arise inside the function tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> CourseTableViewCell when I want to access the UILabels. If I were to put something like cell.titleLabel.text = "Course Title" I get the following error message:
fatal error: unexpectedly found nil while unwrapping an Optional value
Where am I doing things wrong? Would appreciate any help, thanks!
As explained in the last answer in UITableView Using Swift , it is an Xcode bug. Add the following:
override func tableView(tableView:UITableView!, heightForRowAtIndexPath indexPath:NSIndexPath)->CGFloat {
return 44
}
(or whatever height you want) and you'll be ok.
I duplicated your code and verified the solution.
Apologies, I forgot something else: you must not registerClass:forCellReuseIdentifier. This is already done when you set up your table and prototype cell in interface builder.
Sorry to reply after so much time has passed but I tear my hair on this exact problem this whole weekend. This bug is still there on XCode 8.3.2 (8E2002), this is the latest one as I write these lines. I had the exact same problem as the OP and adding
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 44
}
did not worked for me. The only thing that worked for me was removing this from my viewDidLoad:
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
// REMOVE THIS v v v v v
self.tableView.register(CustomTableViewCell.self, forCellReuseIdentifier: "MyCustomCell")
// REMOVE THIS ^ ^ ^ ^ ^
// Do whatever you want here…
}
The heightForRowAt indexPath is ineffective, you don't need to use it to fix it.
I hope this helped someone too !