I am trying to implement JTAppleCalendar programmatically without storyboards, using a xib file for the cell. I have set the delegate and datasource, and implemented the required functions, but the cells are not showing. I can see that the collection view is set up and visible in the Viewcontroller(the blue square in image in link 2), and the configureCalendar() and cellForItemAt() are called, but still no data is shown.

What am I missing?

    var calendarView: JTAppleCalendarView!

  override func viewDidLoad() {
    super.viewDidLoad()

    calendarView = JTAppleCalendarView(frame: CGRect(x: 0, y: 0, width: 300, height: 300))
    calendarView.register(CalendarCellView.self, forCellWithReuseIdentifier: "cell")
    calendarView.ibCalendarDelegate = self
    calendarView.ibCalendarDataSource = self
    self.view.addSubview(calendarView)
    self.view.bringSubview(toFront: calendarView)
    self.calendarView.backgroundColor = UIColor.blue
}

extension TestViewController: JTAppleCalendarViewDataSource {
   func configureCalendar(_ calendar: JTAppleCalendarView) -> ConfigurationParameters {
    let formatter = DateFormatter()
    formatter.dateFormat = "yyyy MM dd"

    let startDate = formatter.date(from: "2016 02 01")! // You can use date generated from a formatter
    let endDate = Date()                                // You can also use dates created from this function
    let parameters = ConfigurationParameters(startDate: startDate,
                                             endDate: endDate,
                                             numberOfRows: 6, // Only 1, 2, 3, & 6 are allowed
        calendar: Calendar.current,
        generateInDates: .forAllMonths,
        generateOutDates: .tillEndOfGrid,
        firstDayOfWeek: .sunday)
    return parameters
}

func calendar(_ calendar: JTAppleCalendarView, willDisplay cell: JTAppleCell, forItemAt date: Date, cellState: CellState, indexPath: IndexPath) {

    }
}

extension TestViewController: JTAppleCalendarViewDelegate {
  func calendar(_ calendar: JTAppleCalendarView, cellForItemAt date: Date, cellState: CellState, indexPath: IndexPath) -> JTAppleCell {

    let cell = calendar.dequeueReusableJTAppleCell(withReuseIdentifier: "cell", for: indexPath) as! CalendarCellView
    cell.dayLabel?.text = cellState.text
    print(cellState.text)

    return cell
  }  
}



class CalendarCellView: JTAppleCell {

@IBOutlet var dayLabel: UILabel!
@IBOutlet var taskImage: UIImageView!

override func awakeFromNib() {
    dayLabel.textColor = UIColor.red
    self.backgroundColor = UIColor.blue
  }   
}

screenschot of xib cell

screenshot of how the collectionview currently looks

Layout

JTAppleCalendarView's super class is UICollectionView and it uses UICollectionViewFlowLayout to layout the items.JTAppleCalendarView provides CellSize to configure the item size and you also can use UICollectionViewFlowLayout to configure Min Spacing.

Using Custom Cell

I guess you were using xib to Custom Cell, so you have to use register(_ nib: UINib?, forCellWithReuseIdentifier identifier: String) to register the Cell.Finally, don't forget to add constraints for the dayLabel.

Example

calendarView's Cell Size is 40, width is 280(7 columns) and height is 240(six rows), Min Spacing for cells and lines are 0.