How to pass data between container view and main view controller properly - ios

Question

I'm dealing with following problem: On main VC I have a TableView, and on container view controller I have a textField. I want to add every text, I'm typing in container automatically appears as a new row on tableView in main VC
By now I'm using segue to send data from main VC to container. But what should I implement to do the same in a reverse order? I though of implementing delegate of main VC in my container view, but I have no idea how to do that properly. Or maybe there is exist more common solution.
Anyway, here is my code:
class MessageViewController: UIViewController {
var currentUser: User!
var containerViewController: InputTextViewController?
#IBOutlet weak var enterMessageView: UIView!
#IBOutlet weak var messageTableView: UITableView!
}
extension MessageViewController {
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "moveToInputText" {
let connectContainerViewController = segue.destination as? InputTextViewController
containerViewController = connectContainerViewController
containerViewController?.userSendMessageTo = currentUser
}
}
}
extension MessageViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return currentUser.mesaageHistory.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "messageCell") as! ChatMessageTableViewCell
let data = currentUser.mesaageHistory[indexPath.row]
cell.messageLabel.text = data.messageText
return cell
}
}
class InputTextViewController: UIViewController {
#IBOutlet weak var messageTextField: UITextField!
var userSendMessageTo: User!
weak var delegate = MessageViewController()
#IBAction func sendMessge(_ sender: Any) {
handleSend()
userSendMessageTo.mesaageHistory.append(message)
print(userSendMessageTo.mesaageHistory[0].messageText)
let row = userSendMessageTo.mesaageHistory.count - 1
let insertIndexPath = IndexPath(item: row, section: 0)
print(userSendMessageTo.mesaageHistory.count)
delegate?.messageTableView.beginUpdates()
delegate?.messageTableView.insertRows(at: [insertIndexPath], with: UITableViewRowAnimation.automatic)
delegate?.messageTableView.endUpdates()
}
}

Answer 1

Here's how to use the 'delegate' pattern properly
Protocol declaration & delegate member
protocol InputTextViewControllerDelegate: class {
func someFunc()
func anotherFunc()
}
class InputTextViewController: UIViewController {
weak var delegate: InputTextViewControllerDelegate?
}
Protocol implementation & setting the delegate property
extension MessageViewController, InputTextViewControllerDelegate {
// MARK: InputTextViewControllerDelegate
//
func someFunc()
{
}
func anotherFunc()
{
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "moveToInputText" {
let connectContainerViewController = segue.destination as? InputTextViewController
containerViewController = connectContainerViewController
containerViewController
}
}
}