Data not passing in Swift - swift

Question

I'm working on a journal app and now I want people to be able to click on a cell/entry and then go to a more detailed view where they can read/edit their entry. The thing is, the strings I'm trying to pass to the next view aren't coming through.
Edit:
This is the code on the TableViewController:
class TableViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var items: [Entry] = []
var passedEntry:String = ""
func fetchData() {
do {
items = try context.fetch(Entry.fetchRequest())
print(items)
DispatchQueue.main.async {
self.tableView.reloadData()
}
} catch {
print("Couldn't fetch data")
}
}
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as UITableViewCell
let date = items.reversed()[indexPath.row].date
cell.textLabel?.text = items[indexPath.row].title
if let date = date {
let dateStamp = "Added on \(date)"
cell.detailTextLabel?.text = dateStamp
}
return cell
}
#objc(tableView:editActionsForRowAtIndexPath:) func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let delete = UITableViewRowAction(style: .default, title: "Delete") { (action, indexPath) in
// delete item at indexPath
let item = self.items[indexPath.row]
self.context.delete(item)
(UIApplication.shared.delegate as! AppDelegate).saveContext()
self.items.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
}
return [delete]
}
public func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){
if (segue.identifier == "showEntry") {
// initialize new view controller and cast it as your view controller
let viewController = EntryViewController()
// your new view controller should have property that will store passed value
viewController.passedEntry = passedEntry
}
}
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
passedEntry = items[indexPath.row].title!
self.performSegue(withIdentifier: "showEntry", sender: self)
}
override func viewWillAppear(_ animated: Bool) {
fetchData()
}
This is the code on the EntryViewController which still prints nil:
class EntryViewController: UIViewController {
var passedEntry:String!
#IBOutlet weak var dreamTitle: UITextView!
#IBOutlet weak var dreamPost: UITextView!
#IBAction func saveChanges(_ sender: Any) {
}
override func viewWillAppear(_ animated: Bool) {
print(passedEntry)
}
I'm sorry for being a newbie, but I need some more detailed instructions...

Answer 1

Two issues:
The signature of prepareForSegue is wrong for Swift 3.
Never create view controllers with the default initializer when using storyboard
This main issue occurs in this line:
let viewController = EntryViewController()
You are creating a brand new instance of EntryViewController which is not the controller in the storyboard. You have to use the destination view controller of the segue:
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showEntry" {
// initialize new view controller and cast it as your view controller
let viewController = segue.destination as! EntryViewController
// your new view controller should have property that will store passed value
let title = items[indexPath.row].title
viewController.passedEntry = title
}
}
And I recommend to declare the string in the destination view controller as non-optional empty string rather than an implicit unwrapped optional. Non-optional types will never crash the app.
var passedEntry = ""

Answer 2

You are defining prepareForSegue() as a local function inside the tableView-function. It will not be used. Put a debugger breakpoint into it and see yourself if it will be reached.