Pass data to previous tableviewcell in swift 3 - uitableview

Question

I have created 3 outlets for labels,2 actions for buttons and 1 outlet for UIDatePickerView. lblField displays the current date with month, date and year. lblField2 displays the selected dates by the user after pressing dueDate action. lblField3 displays the differences between the current date and selected date.
When I click on the cell of Due date: it opens DatePickerViewController as given above.
Now I need to pass data of lblField3 of DatePickerViewController to "Due date: " cell of TodayViewController in Swift 3 after pressing Done button. How shall I do it using simple way in Swift 3?

Answer 1

For that you need to simply use delegate/protocol. Create one delegate and create its instance in the DatePickerViewController, Now implement that protocol with your TodayViewController and when you move to the DatePickerViewController set its delegate to the self. Now simply call the delegate method on DatePickerViewController to pass the data.
protocol DatePickerDelegate {
func getDifference(diff: String)
}
Now create its instance in DatePickerViewController and call the method where you get the difference of date.
class DatePickerViewController: UIViewController {
var delegate: DatePickerDelegate?
//Other instances property declaration ...
//other methods
#IBAction func Done(_ sender: Any) {
self.delegate?.getDifference(diff: lblField3.text ?? "")
_ = self.navigationController?.popViewController(animated: true)
}
}
Now simply implement DatePickerDelegate with your TodayViewController and add its method.
class TodayViewController: UIViewController, DatePickerDelegate, UITableViewDelegate, UITableViewDataSource {
//Other methods
//Set the delegate when you are push to DatePickerViewController
let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "DatePickerViewController") as! DatePickerViewController
//Set delegate of DatePickerViewController
secondViewController.delegate = self
selectedIndexPath = indexPath
self.navigationController?.pushViewController(secondViewController, animated: true)
//DatePickerDelegate method
func getDifference(diff: String) {
//Access diff here
print(diff)
}
}
Edit: The problem is in didSelectRowAt you are comparing the text of cell's label instead of that you need to compare the row of tableView
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if (tableView.tag == 1) {
if indexPath.row == 4 {
//Show view for Baby size guide:
let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "BabySizeViewController") as! BabySizeViewController
selectedIndexPath = indexPath
self.navigationController?.pushViewController(secondViewController, animated: true)
}
else if indexPath.row == 1 {
//Show view for Due date:
let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "DatePickerViewController") as! DatePickerViewController
selectedIndexPath = indexPath
secondViewController.delegate = self
self.navigationController?.pushViewController(secondViewController, animated: true)
}
}
}