Swift- UsersDefault Array not updating/reloading TableView when popViewController back
Question
I have a yearOne Class, fallQuarterCell Class as one view controller file and SearchPage Class as another view controller file. I'm trying to append the data array when the user pressed on a cell to the data array which I set in fallQuarterCell and assigned with UsersDefaults .
It does append to the data array but it only shows up when I'm moving from the view controller before yearOne / fallQuarterCell to yearOne / fallQuarterCell but when I go back using popViewController from SearchPage view controller, it does not show up and update the tableView . I tried to use viewWillAppear and all sorts but I'm still having trouble.
import UIKit
class yearOne: UICollectionViewController{
let customCellIdentifier = "cellID"
let customCellIdentifier2 = "cellID2"
let customCellIdentifier3 = "cellID3"
let customCellIdentifier4 = "cellID4"
let quarters = [
customLabel (title: "Fall Quarter"),
customLabel (title: "Winter Quarter"),
customLabel (title: "Spring Quarter"),
customLabel (title: "Summer Quarter")
]
let vc = fallQuarterCell()
let vc2 = winterQuarterCell()
let vc3 = springQuarterCell()
let vc4 = summerQuarterCell()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
collectionView.reloadData()
vc.load()
vc2.load()
vc3.load()
vc4.load()
collectionView.reloadData()
}
override func viewDidLoad() {
super.viewDidLoad()
collectionView.dataSource = self
collectionView.delegate = self
self.collectionView!.register(fallQuarterCell.self, forCellWithReuseIdentifier: customCellIdentifier)//
self.collectionView!.register(winterQuarterCell.self, forCellWithReuseIdentifier: customCellIdentifier2)
self.collectionView!.register(springQuarterCell.self, forCellWithReuseIdentifier: customCellIdentifier3)
self.collectionView!.register(summerQuarterCell.self, forCellWithReuseIdentifier: customCellIdentifier4)
navigationItem.title = "Year One"
navigationController?.navigationBar.prefersLargeTitles = true
collectionView?.backgroundColor = .lightGray
//navigationItem.prompt = "Click the + button to add courses, Swipe left on a course to delete."
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return quarters.count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if (indexPath.row == 0){
let cell1 = collectionView.dequeueReusableCell(withReuseIdentifier: customCellIdentifier, for: indexPath) as! fallQuarterCell
cell1.layer.borderColor = UIColor.orange.cgColor
cell1.layer.borderWidth = 2
cell1.layer.cornerRadius = 5
cell1.quarters = self.quarters[0]
return cell1
}
else if (indexPath.row == 1){
let cell2 = collectionView.dequeueReusableCell(withReuseIdentifier: customCellIdentifier2, for: indexPath) as! winterQuarterCell
cell2.layer.borderColor = UIColor.blue.cgColor
cell2.layer.borderWidth = 2
cell2.layer.cornerRadius = 5
cell2.quarters = self.quarters[1]
return cell2
}
else if (indexPath.row == 2){
let cell3 = collectionView.dequeueReusableCell(withReuseIdentifier: customCellIdentifier3, for: indexPath) as! springQuarterCell
cell3.layer.borderColor = UIColor.green.cgColor
cell3.layer.borderWidth = 2
cell3.layer.cornerRadius = 5
cell3.quarters = self.quarters[2]
return cell3
}
else if (indexPath.row == 3){
let cell4 = collectionView.dequeueReusableCell(withReuseIdentifier: customCellIdentifier4, for: indexPath) as! summerQuarterCell
cell4.layer.borderColor = UIColor.red.cgColor
cell4.layer.cornerRadius = 5
cell4.quarters = self.quarters[3]
return cell4
}
else{
return UICollectionViewCell()
}
}
@objc func buttonAction(sender: UIButton!) {
switch sender.tag {
case 0:
let destination = SearchPage()
destination.tag = sender.tag
navigationController?.pushViewController(destination, animated: true)
case 1:
let destination = SearchPage()
destination.tag = sender.tag
navigationController?.pushViewController(destination, animated: true)
case 2:
let destination = SearchPage()
destination.tag = sender.tag
navigationController?.pushViewController(destination, animated: true)
case 3:
let destination = SearchPage()
destination.tag = sender.tag
navigationController?.pushViewController(destination, animated: true)
default:
let destination = SearchPage()
destination.tag = sender.tag
navigationController?.pushViewController(destination, animated: true)
}
}
}
extension yearOne : UICollectionViewDelegateFlowLayout{
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let width = (view.frame.width - 30)
return CGSize(width: width, height: 200)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 8
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 1
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
UIEdgeInsets(top: 30, left: 10, bottom: 30, right: 10)
}
}
class fallQuarterCell: UICollectionViewCell, UITableViewDelegate, UITableViewDataSource {
var data = UserDefaults.standard.object(forKey: "SavedArray") as? [String] ?? [String](){
didSet {
tableView.reloadData()
}
}
func load(){
if let loadeddata: [String] = UserDefaults.standard.object(forKey: "SavedArray") as? [String] {
data = loadeddata
tableView.reloadData()
}
}
let cellId = "coursesName"
let tableView:UITableView = {
let tableView = UITableView()
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.backgroundColor = UIColor.white
return tableView
}()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
cell.textLabel?.text = data[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 40
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if (editingStyle == .delete) {
// handle delete (by removing the data from your array and updating the tableview)
if (indexPath.row == 0){
data.remove(at: 0)
UserDefaults.standard.set(data, forKey: "SavedArray")
self.tableView.reloadData()
}
else if (indexPath.row == 1){
data.remove(at: 1)
UserDefaults.standard.set(data, forKey: "SavedArray")
self.tableView.reloadData()
}
else if (indexPath.row == 2){
data.remove(at: 2)
UserDefaults.standard.set(data, forKey: "SavedArray")
self.tableView.reloadData()
}
else if (indexPath.row == 3){
data.remove(at: 3)
UserDefaults.standard.set(data, forKey: "SavedArray")
self.tableView.reloadData()
}
else if (indexPath.row == 4){
data.remove(at: 4)
UserDefaults.standard.set(data, forKey: "SavedArray")
self.tableView.reloadData()
}
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
//add class information???
}
var quarters: customLabel? {
didSet {
guard let quarters = quarters else {return}
quarterLabel.text = quarters.title
}
}
override init(frame: CGRect){
super.init(frame: frame)
addSubview(tableView)
setupView()
}
func setupView(){
tableView.delegate = self
tableView.dataSource = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellId)
self.backgroundColor = UIColor.white
contentView.addSubview(quarterLabel)
contentView.addSubview(addButton)
quarterLabel.translatesAutoresizingMaskIntoConstraints = false
quarterLabel.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 10).isActive = true
quarterLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 10).isActive = true
addButton.translatesAutoresizingMaskIntoConstraints = false
addButton.topAnchor.constraint(equalTo: quarterLabel.topAnchor, constant: -5).isActive = true
addButton.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -10).isActive = true
addButton.heightAnchor.constraint(equalToConstant: 25).isActive = true
addButton.widthAnchor.constraint(equalToConstant: 25).isActive = true
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 35).isActive = true
tableView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 5).isActive = true
tableView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -10).isActive = true
tableView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -5).isActive = true
// each collection view cell (row) = should display xxQuarter Array
// call indexpath for the collection view and set the tableview to the collection view
// quarterCell.indexPath
//if(buttonAction) is cicked from searchPage(), then add the UI label
//remove course function, add course function
}
let quarterLabel : UILabel = {
let label = UILabel()//frame: CGRect(x: 15, y: -75, width: 300, height: 50))
label.translatesAutoresizingMaskIntoConstraints = false
label.textColor = UIColor.black
label.font = UIFont.boldSystemFont(ofSize: 16)
//label.textAlignment = .center
return label
}()
let addButton : UIButton = {
let button = UIButton()//frame: CGRect(x: 345, y: 10, width: 30, height: 30))
button.setImage(UIImage(named: "addicon"), for: .normal)
button.imageEdgeInsets = UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5)
button.tag = 0
button.addTarget(self, action: #selector(yearOne.buttonAction), for: .touchUpInside)
return button
}()
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class winterQuarterCell: UICollectionViewCell, UITableViewDelegate, UITableViewDataSource {
var data = UserDefaults.standard.object(forKey: "SavedArray2") as? [String] ?? [String](){
didSet {
tableView.reloadData()
}
}
func load(){
if let loadeddata: [String] = UserDefaults.standard.object(forKey: "SavedArray2") as? [String] {
data = loadeddata
tableView.reloadData()
}
}
let cellId = "coursesName"
let tableView:UITableView = {
let tableView = UITableView()
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.backgroundColor = UIColor.white
return tableView
}()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
cell.textLabel?.text = data[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 40
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if (editingStyle == .delete) {
// handle delete (by removing the data from your array and updating the tableview)
if (indexPath.row == 0){
data.remove(at: 0)
UserDefaults.standard.set(data, forKey: "SavedArray2")
self.tableView.reloadData()
}
else if (indexPath.row == 1){
data.remove(at: 1)
UserDefaults.standard.set(data, forKey: "SavedArray2")
self.tableView.reloadData()
}
else if (indexPath.row == 2){
data.remove(at: 2)
UserDefaults.standard.set(data, forKey: "SavedArray2")
self.tableView.reloadData()
}
else if (indexPath.row == 3){
data.remove(at: 3)
UserDefaults.standard.set(data, forKey: "SavedArray2")
self.tableView.reloadData()
}
else if (indexPath.row == 4){
data.remove(at: 4)
UserDefaults.standard.set(data, forKey: "SavedArray2")
self.tableView.reloadData()
}
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
//add class information???
}
var quarters: customLabel? {
didSet {
guard let quarters = quarters else {return}
quarterLabel.text = quarters.title
}
}
override init(frame: CGRect){
super.init(frame: frame)
addSubview(tableView)
setupView()
}
func setupView(){
tableView.delegate = self
tableView.dataSource = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellId)
self.backgroundColor = UIColor.white
contentView.addSubview(quarterLabel)
contentView.addSubview(addButton)
quarterLabel.translatesAutoresizingMaskIntoConstraints = false
quarterLabel.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 10).isActive = true
quarterLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 10).isActive = true
addButton.translatesAutoresizingMaskIntoConstraints = false
addButton.topAnchor.constraint(equalTo: quarterLabel.topAnchor, constant: -5).isActive = true
addButton.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -10).isActive = true
addButton.heightAnchor.constraint(equalToConstant: 25).isActive = true
addButton.widthAnchor.constraint(equalToConstant: 25).isActive = true
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 35).isActive = true
tableView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 5).isActive = true
tableView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -10).isActive = true
tableView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -5).isActive = true
// each collection view cell (row) = should display xxQuarter Array
// call indexpath for the collection view and set the tableview to the collection view
// quarterCell.indexPath
//if(buttonAction) is cicked from searchPage(), then add the UI label
//remove course function, add course function
}
let quarterLabel : UILabel = {
let label = UILabel()//frame: CGRect(x: 15, y: -75, width: 300, height: 50))
label.translatesAutoresizingMaskIntoConstraints = false
label.textColor = UIColor.black
label.font = UIFont.boldSystemFont(ofSize: 16)
//label.textAlignment = .center
return label
}()
let addButton : UIButton = {
let button = UIButton()//frame: CGRect(x: 345, y: 10, width: 30, height: 30))
button.setImage(UIImage(named: "addicon"), for: .normal)
button.imageEdgeInsets = UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5)
button.tag = 1
button.addTarget(self, action: #selector(yearOne.buttonAction), for: .touchUpInside)
return button
}()
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
....
}
Section of the SearchPage Class:
let vc = fallQuarterCell()
let vc2 = winterQuarterCell()
let vc3 = springQuarterCell()
let vc4 = summerQuarterCell()
var tag: Int?
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
tableView.deselectRow(at: indexPath, animated: true)
if (tag == 0){
if (resultSearchController.isActive){
vc.data.append(filteredCourses[indexPath.row])
UserDefaults.standard.set(vc.data, forKey: "SavedArray")
navigationController?.popViewController(animated: true)
}
else{
vc.data.append(allCourses[indexPath.row] as! String)
UserDefaults.standard.set(vc.data, forKey: "SavedArray")
navigationController?.popViewController(animated: true)
}
}
else if (tag == 1){
if (resultSearchController.isActive){
vc2.data.append(filteredCourses[indexPath.row])
UserDefaults.standard.set(vc2.data, forKey: "SavedArray2")
navigationController?.popViewController(animated: true)
}
else{
vc2.data.append(allCourses[indexPath.row] as! String)
UserDefaults.standard.set(vc2.data, forKey: "SavedArray2")
navigationController?.popViewController(animated: true)
}
}
.....
}
1 answers
solution1
1 2020-02-12 00:33:34
It seems like you need to call your collectionView's reloadData() method here:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
UserDefaults.standard.synchronize()
vc.load()
collectionView.reloadData()
}
The reason is that when you go to the Select Courses page -> New ViewController is pushed on top of your yearOne and when you go back -> New ViewController is just removed from the view hierarchy and yearOne becomes a top one.
The collection view is not reloaded automatically since it was loaded already and not reloadData() is called.
But when you go back -> yearOne VC is destroyed. Then you open and create it again from the scratch and collection view loads new data from the defaults.
PS There are things that are not clear from the code provided:
- What you return as cell for your collection view in yearOne view controller.
- Why you are creating cells outside of UICollectionViewDataSource methods?
- Why you are creating NEW instatnces of yearOne and fallQuarterCell from SearchPage class?
- What you return as cell for your table view in fallQuarterCell class?
- No need to call viewWillAppear explicitly since it will be called when the yearOne is about to be shown on the screen.
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