Passing CoreData keys to new ViewController - ios

Question

I am working on one part of my app which will function as a journal for the user, in which they can add an entry, then review or delete them afterwards. I followed a few Swift tutorials for CoreData and I have confirmed that the CoreData setup is working. However, I am having trouble getting values to pass to the UIViewController that will display the journal after already being saved. In one configuration I had tried it displayed no data, in another the data would stay the same no matter what entry selected, and in the setup below, this line journalEntryViewer.journalViewerTextView.text = journalTextToPass returns "found nil when unwrapping optional value."
Here is the code for the UITableViewController that acts as the list:
import UIKit
import CoreData
class JournalCollectionViewer: UITableViewController {
var JournalEntry = [NSManagedObject]()
var journalTextToPass:String!
var journalTitleToPass:String!
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
self.tableView.reloadData()
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext
let fetchRequest = NSFetchRequest(entityName: "JournalEntry")
do {
let results =
try managedContext.executeFetchRequest(fetchRequest)
JournalEntry = results as! [NSManagedObject]
} catch let error as NSError {
print("Could not fetch \(error), \(error.userInfo)")
}
}
// MARK: - Table view data source
#IBOutlet weak internal var journalCollectionTable: UITableView!
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return JournalEntry.count
}
override func tableView(tableView: UITableView,
cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell =
tableView.dequeueReusableCellWithIdentifier("JournalCell")
let entry = JournalEntry[indexPath.row]
cell!.textLabel!.text =
entry.valueForKey("journalDate") as? String
return cell!
}
func selectedTableCell(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let entry = self.JournalEntry[indexPath.row]
self.performSegueWithIdentifier("ShowEntryViewer", sender: entry)
}
// MARK: - Navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowEntryViewer" {
let journalEntryViewer = segue.destinationViewController as! JournalEntryViewer
journalEntryViewer.self.navigationItem.title = journalTitleToPass
journalEntryViewer.journalViewerTextView.text = journalTextToPass
}
}
}
In the Swift file for the viewer (journalEntryViewer), all I have done is declared the class and the UITextView. Needless to say, I am at a loss. Any help appreciated!

Answer 1

When you assign value to the IBOutlet object in the prepareForSegue method that time it is not initialized, so you need to pass the string object and assign that string object to the journalViewerTextView in the viewDidLoadof JournalEntryViewer.
First declare two instance var in the JournalEntryViewer like this
var journalTitle: String?
var journalText: String?
Now use this var in viewDidload
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.title = journalTitle
self.journalViewerTextView.text = journalTitle
}
Now pass this journalTitle and journalText in the prepareForSegue method of JournalCollectionViewer
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowEntryViewer" {
let journalEntryViewer = segue.destinationViewController as! JournalEntryViewer
journalEntryViewer.journalTitle = journalTitleToPass
journalEntryViewer.journalText = journalTextToPass
}
}
New Edit:
Problem with your code is you have not used delegate method didSelectRowAtIndexPath instead of you are using something else selectedTableCell that is wrong try to implement delegate method of UITableView
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let entry = self.JournalEntry[indexPath.row]
self.performSegueWithIdentifier("ShowEntryViewer", sender: entry)
}
Now you are passing entry object so change your prepareForSegue like this
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowEntryViewer" {
let journalEntryViewer = segue.destinationViewController as! JournalEntryViewer
let entry = sender as! NSManagedObject
journalEntryViewer.journalTitle = entry.valueForKey("journalDate") as? String
journalEntryViewer.journalText = entry.valueForKey("journalEntryText") as? String
}
}