Swift CVCalendar not updating monthLabel - ios

Question

I recently started using CVCalendar to create a CalendarView with a Week presentation.
I created a UILabel called monthLabel which has an outlet to the view's controller
The ViewController for this particular view is this one:
import UIKit
import CVCalendar
class EventsViewController: UIViewController {
#IBOutlet weak var headerView: UIView!
#IBOutlet weak var menuView: CVCalendarMenuView!
#IBOutlet weak var calendarView: CVCalendarView!
#IBOutlet weak var eventsTable: UITableView!
#IBOutlet weak var monthLabel: UILabel!
private var currentCalendar: Calendar?
private var animationFinished: Bool = true
let mainAppViewHeader: MainAppViewHeader = UIView.fromNib()
override func viewDidLoad() {
super.viewDidLoad()
loadViewHeader()
setupTable()
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
setupDatePicker()
}
override func awakeFromNib() {
let timeZoneBias = 480 // (UTC+08:00)
currentCalendar = Calendar(identifier: .gregorian)
currentCalendar?.locale = Locale(identifier: "fr_FR")
if let timeZone = TimeZone(secondsFromGMT: -timeZoneBias * 60) {
currentCalendar?.timeZone = timeZone
}
}
func setupDatePicker() {
menuView.delegate = self
calendarView.delegate = self
menuView.backgroundColor = ColorManager.Gray5
calendarView.backgroundColor = ColorManager.Gray5
calendarView.appearance.dayLabelPresentWeekdaySelectedBackgroundColor = ColorManager.PrimaryColor
calendarView.appearance.dayLabelWeekdaySelectedBackgroundColor = ColorManager.PrimaryColor
if let currentCalendar = currentCalendar {
monthLabel.text = CVDate(date: Date(), calendar: currentCalendar).globalDescription
}
menuView.commitMenuViewUpdate()
calendarView.commitCalendarViewUpdate()
}
func loadViewHeader() {
mainAppViewHeader.setupHeader()
headerView.addSubview(mainAppViewHeader)
}
func setupTable() {
let rowNib = UINib(nibName: "EventTableCell", bundle: nil)
eventsTable.dataSource = self
eventsTable.delegate = self
eventsTable.register(rowNib, forCellReuseIdentifier: "eventCell")
eventsTable.separatorStyle = .none
}
}
extension EventsViewController: CVCalendarViewDelegate, CVCalendarMenuViewDelegate {
func presentationMode() -> CalendarMode {
return .weekView
}
func firstWeekday() -> Weekday {
return .sunday
}
func shouldAutoSelectDayOnWeekChange() -> Bool {
return true
}
func disableScrollingBeforeDate() -> Date {
let currentDate = Date()
return currentDate.addingTimeInterval(-8 * 24 * 60 * 60)
}
func disableScrollingBeyondDate() -> Date {
let currentDate = Date()
return currentDate.addingTimeInterval(180 * 24 * 60 * 60)
}
func maxSelectableRange() -> Int {
return 1
}
func shouldSelectRange() -> Bool {
false
}
func earliestSelectableDate() -> Date {
let currentDate = Date()
return currentDate.addingTimeInterval(-8 * 24 * 60 * 60)
}
func latestSelectableDate() -> Date {
let currentDate = Date()
return currentDate.addingTimeInterval(180 * 24 * 60 * 60)
}
func shouldShowWeekdaysOut() -> Bool {
return true
}
func didShowPreviousWeekView(from startDayView: DayView, to endDayView: DayView) {
print(startDayView, endDayView)
}
func presentedDateUpdated(_ date: CVDate) {
monthLabel.text = "asdf" //calendarView.presentedDate.globalDescription
print(date.globalDescription)
}
}
extension EventsViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let eventCell = tableView.dequeueReusableCell(withIdentifier: "eventCell") as? EventTableCell else {
return UITableViewCell()
}
eventCell.setupCell()
eventCell.updateConstraintsIfNeeded()
return eventCell
}
}
extension EventsViewController: UITableViewDelegate {
}
And the outlet reference:
The issue here is that even tho I'm telling the UILabel to change its text whenever the presented date is updated:
func presentedDateUpdated(_ date: CVDate) {
monthLabel.text = "asdf" //calendarView.presentedDate.globalDescription
print(date.globalDescription)
}
It's not updating its value, yet I get the date.globalDescription value printed in the console.
Is there something I'm missing when trying to update the label?
I tried using the code in the official example:
func presentedDateUpdated(_ date: CVDate) {
if monthLabel.text != date.globalDescription && self.animationFinished {
let updatedMonthLabel = UILabel()
updatedMonthLabel.textColor = monthLabel.textColor
updatedMonthLabel.font = monthLabel.font
updatedMonthLabel.textAlignment = .center
updatedMonthLabel.text = date.globalDescription
updatedMonthLabel.sizeToFit()
updatedMonthLabel.alpha = 0
updatedMonthLabel.center = self.monthLabel.center
let offset = CGFloat(48)
updatedMonthLabel.transform = CGAffineTransform(translationX: 0, y: offset)
updatedMonthLabel.transform = CGAffineTransform(scaleX: 1, y: 0.1)
UIView.animate(withDuration: 0.35, delay: 0, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.animationFinished = false
self.monthLabel.transform = CGAffineTransform(translationX: 0, y: -offset)
self.monthLabel.transform = CGAffineTransform(scaleX: 1, y: 0.1)
self.monthLabel.alpha = 0
updatedMonthLabel.alpha = 1
updatedMonthLabel.transform = CGAffineTransform.identity
}) { _ in
self.animationFinished = true
self.monthLabel.frame = updatedMonthLabel.frame
self.monthLabel.text = updatedMonthLabel.text
self.monthLabel.transform = CGAffineTransform.identity
self.monthLabel.alpha = 1
updatedMonthLabel.removeFromSuperview()
}
self.view.insertSubview(updatedMonthLabel, aboveSubview: self.monthLabel)
}
}
But this approach is only pushing a new view with the updated month and then dismissing the view, and while it contains basically the same code that I was using:
self.monthLabel.text = updatedMonthLabel.text
The monthLabel is not being updated, this is what happens when using the above code, it reverts back to original text.
If I remove this line:
updatedMonthLabel.removeFromSuperview()
Both texts get overlapped, so it's ignoring this line:
self.monthLabel.text = updatedMonthLabel.text
I've done some extra testing, and checked that the label is correctly linked with an outlet to my view, I changed the text color:
func presentedDateUpdated(_ date: CVDate) {
print(Thread.current)
print("Wololo")
monthLabel.textColor = UIColor.green
monthLabel.text = "asdf"
// calendarView.contentController.refreshPresentedMonth()
// monthLabel.text = "asdf" //calendarView.presentedDate.globalDescription
// print(date.globalDescription)
}
It prints:
<NSThread: 0x600002b6c100>{number = 1, name = main}
Wololo
N number of times I change the day by clicking on the calendar, however the text remains unchanged:

Answer 1

For some reason the code inside:
override func awakeFromNib() {
let timeZoneBias = 480 // (UTC+08:00)
currentCalendar = Calendar(identifier: .gregorian)
currentCalendar?.locale = Locale(identifier: "fr_FR")
if let timeZone = TimeZone(secondsFromGMT: -timeZoneBias * 60) {
currentCalendar?.timeZone = timeZone
}
}
was in conflict with not updating the label, if we remove the above code and instead do this:
func setupDatePicker() {
menuView.delegate = self
calendarView.delegate = self
menuView.commitMenuViewUpdate()
calendarView.commitCalendarViewUpdate()
monthLabel.text = calendarView.presentedDate.globalDescription //This line at the bottom of this method
}
Everything works once again.
If someone knows the reason behind it, feel free to make a comment and I'll add it to the answer.

Answer 2

presentedDateUpdated is likely being called on a background thread making it so your UI changes aren't being displayed. you can confirm this by printing Thread.current inside presentedDateUpdated.
a simple solution would be this:
func presentedDateUpdated(_ date: CVDate) {
DispatchQueue.main.async { [weak self] in
self?.monthLabel.text = "asdf" //calendarView.presentedDate.globalDescription
print(date.globalDescription)
}
}