I need the tableView to perform reloadData() after a row has been added via a textView. My tableViews all use the reusable code which works fine.
Below is my Reusable TableViewCode.
class ReusableSubtitleTable: NSObject, UITableViewDataSource, UITableViewDelegate{
let cell = "cell"
var dataArray = [String]()
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) {
print("DataArray count from table view = \(dataArray.count)")
return dataArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let selfSizingCell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! SelfSizingCell
let num = indexPath.row
selfSizingCell.titleText.text = (stepText[num])
selfSizingCell.subtitleText.text = dataArray[num]
return selfSizingCell
}
}
The function below uses the reusable code to display the table which works fine.
class DetailViewController: UIViewController {
let step = 13
var tableView: UITableView!
let dataSource = ReusableSubtitleTable()
var selectedEntry: JournalEntry!
var dataModel = [String]()
var didSave = false
var coreDataManager = CoreDataManager()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = dataSource
tableView.dataSource = dataSource
dataSource.dataArray = dataModel
#IBAction func unwindToDetail( _ sender: UIStoryboardSegue) {
dataModel[10] = step11
didSave = coreDataManager.updateEntry(step11: step11, selectedEntry: selectedEntry)
}
}
The problem come in when a user wants to add to the last row. The user taps a button and is taken to the next controller which is a TextView. When user finishes their entry they tap the 'Save' button which returned to the DetailViewController via an unwind. The selectedEntry is saved and the dataModel updated. Now the table view needs to reload to display this added text.
I've tried adding tableView.ReloadData() after didSave. I've tried a Dispatch and tried saving the data before returning from the textView via the unwind but that doesn't work either.
I tried adding the below function to ReusableTableView and called it after the coredata update - there are no errors but it does not reload the table.
func doReload(){
tableView.reloadData()
}
I have verified that the data is saved and it does displays if I return to the summary controller and then go forward the DetailViewController.
Any help is appreciated.
Placing the UITableView reloadData() within either viewWillAppear or viewDidAppear should resolve this issue.
For example:
func viewDidAppear(_ animated: bool) {
super.viewDidAppear(animated)
tableView.reloadData()
}
This is because the view hierarchy isn't yet regarded as "visible" during the segue unwind and why you see it work by going back to reloading the view controller. The reloadData() function, for efficiency, only redisplays visible cells and at the time of the unwind the cells aren't "visible".
Apple Documentation - UITableView.reloadData():
For efficiency, the table view redisplays only those rows that are
visible.
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 have built a meme generator and I have embedded the view controller that handles the meme creation inside of a tab bar view controller. The first tab displays a table view and I am attempting to have that table view display memes once they are saved via the activity view. I have added a memes array to my App Delegate file (I know this is controversial, but it is a requirement of this exercise) and I have confirmed that the meme is being saved and passed to the app delegate file.
I want to display the saved meme's image and text in the table view whenever the user creates a new meme. Here is what I have and this is not working.
import UIKit
class TableViewMemesViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var memes: [Meme]!
override func viewDidLoad() {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
memes = appDelegate.memes
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return memes.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell")
let meme = memes[indexPath.row]
cell?.imageView?.image = meme.memedImage
cell?.textLabel?.text = meme.topText
return cell!
}
}
Where am I going wrong? The process of cellForRowAt is still new and frustrating for me. Here is a link to the repo.
When you navigate between UITabBar tabs, viewDidLoad is not triggered, it is only triggered once the tab bar has been created.
In order to make the table view reflect the changes, you need to handle that in viewWillAppear not in viewDidLoad.
So you will have:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let appDelegate = UIApplication.shared.delegate as! AppDelegate
memes = appDelegate.memes
}
And you'll need to add a property observer to memes like this:
var memes: [Meme]! {
didSet {
tableView.reloadData()
}
}
Edit: As mentioned by #Andrea Mugnaini, you need to connect an IBOutlet for your table view:
#IBOutlet weak var tableView:UITableView!
I have a view controller containing a table view. In the table view are cells that have a button to delete the data the cell contains. When I press the delete button the cell information is removed from my database but the table view doesn't update until i segue back and forth.
I'm unsure how to access the TableView and force it to re-draw itself from a method inside my table cell.
class EditTaskTableViewCell: UITableViewCell {
//......//
#IBAction func deleteButtonPressed(_ sender: Any) {
let userDefaults = Foundation.UserDefaults.standard
if let userTasks = userDefaults.array(forKey: "userTasks"){
let newArray = removeTask(item: taskNameLabel.text!, from: userTasks as! [String])
userDefaults.set(newArray, forKey: "userTasks")
userDefaults.synchronize()
}
//update table view
}
}
class EditTaskTable_VC: UIViewController, UITableViewDelegate, UITableViewDataSource {
//......//
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = Bundle
.main
.loadNibNamed("EditTaskTableViewCell", owner: self, options: nil)?
.first as! EditTaskTableViewCell
cell.taskName.text = cellData[indexPath.row].title
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cellData.count
}
Try to use delegates.
The example is in Objective C but the general idea is there.
sending reload data from custom tableview cell?
swift delegate example
https://gist.github.com/austinzheng/db58036c4eb825e63e88
I have the following problem:
I am making a Pokédex-like application that displays a list of all 721 Pokémon on the first tab, and another list on the second tab containing My Favorite Pokémon. Essentially, there are two identical ViewControllers connected to my TabBar.
My storyboard is as follows:
So here is the problem:
The TableView on the first (and initial) tab works fine. However, when I load the TableView on the second tab the Pokémon are loaded, but not displayed. I am able to click the TableViewCell and go to the detail page, but the label in the TableViewCell is not showing anything.
This is the code I use for loading Favorites TableView
class FavoritesViewController: BaseViewController,
UITableViewDataSource, UITableViewDelegate {
#IBOutlet var FavoritesListView: UITableView!
var pokemonList: [String] = ["Nothing Here!"]
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("FavoriteCell", forIndexPath: indexPath) as! FavoriteCell
var name = pokemonList[indexPath.row]
capitalizeFirstLetter(&name)
cell.nameLabel.text = name
return cell;
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return pokemonList.count
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
print(pokemonList[indexPath.row])
self.performSegueWithIdentifier("ToPokemonDetail", sender: pokemonList[indexPath.row])
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "ToPokemonDetail"){
let destination = segue.destinationViewController as! PokemonDetailViewController
let thisPokemon = sender as! String
destination.currentPokemon = thisPokemon
}
}
override func viewWillAppear(animated: Bool) {
FavoritesListView.reloadData()
}
override func viewDidLoad() {
super.viewDidLoad()
// Fetch the cached list, getNames returns an array of strings
let list = utility.getNames("Favorites")
pokemonList = list
}
The delegate and the dataSource are set via the storyboard.
The above code works, and shows the Favorites list just fine. The class for the complete Pokédex has a similar construction.
I have tried switching Favorites and Pokédex around, so that it shows the complete Pokémon list on startup. All 721 Pokémon are shown correctly, but then the Favorites are not visible.
What else I have tried:
Checking the Reuse Identifiers, over and over
Referencing outlets should be bound correctly
Calling TableView.reloadData() in the viewDidAppear method
Switching around the tab items
Does anyone have any clue what on earth is going on here?
Feel free to ask any more questions
Edit: this is what happens when I swap the two TabBar Buttons around, no code changes
Pokédex Screen
Favorites Screen
GitHub Project Here
Problem is in storyboard cell label frame. Set constraints of view controller for (Any,Any) Size Class. I can commit the code on github if you can give me write rights on your git. Thanks
Perhaps your table's delegate and dataSource are not set.
table.delegate = self
table.dataSource = self
Of course this is after you add the properties to your view controller
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
Your number of rows is always 0 for that controller,
I looked into your code pokemonList count is always 0 its not updating data in it
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return pokemonList.count
}
The big issue is your PokemonDetailViewController is not a UITableViewController. It needs to inherent from UITableViewDataSource, UITableViewDelegate and then be connected to the storyboard view to provide data and formatting for a table.