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iosswiftswift2tableviewuistoryboardsegue

Data not being transferred between view controllers Swift


When a EventTableViewController proceeds to UserEventViewController or EventViewController the data is not transferred as the labels etc. are not updated to the transferred information. I have tried fix it but it still doesn't work. Please Help.

Any help would be great thanks. Link to project: https://www.dropbox.com/s/1d4d8opuxzpcuk4/TicketekApp.zip?dl=0

Code:

//  EventTableViewController.swift



import UIKit

class EventTableViewController: UITableViewController {
// MARK: Properties

var events = [Event]()
var isAdmin = true
override func viewDidLoad() {
    super.viewDidLoad()

    // Use the edit button item provided by the table view controller.
    navigationItem.leftBarButtonItem = editButtonItem()

    // Load any saved events, otherwise load sample data.
    if let savedEvents = loadEvents() {
        events += savedEvents
    } else {
        // Load the sample data.
        loadSampleEvents()
    }
}

func loadSampleEvents() {
    let photo1 = UIImage(named: "event1")!
    let event1 = Event(name: "ACDC", photo: photo1, rating: 4, price: 500.0, eventDescription: "Album", album: "Album1")!

    let photo2 = UIImage(named: "event2")!
    let event2 = Event(name: "Cold Play", photo: photo2, rating: 5, price: 500.0, eventDescription: "Album", album: "Album1")!

    let photo3 = UIImage(named: "event3")!
    let event3 = Event(name: "One Direction", photo: photo3, rating: 3, price: 500.0, eventDescription: "Album", album: "Album1")!

    events += [event1, event2, event3]
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return events.count
}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    // Table view cells are reused and should be dequeued using a cell identifier.
    let cellIdentifier = "EventTableViewCell"
    let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! EventTableViewCell

    // Fetches the appropriate event for the data source layout.
    let event = events[indexPath.row]

    cell.nameLabel.text = event.name
    cell.photoImageView.image = event.photo
    cell.ratingControl.rating = event.rating
    cell.priceLabel.text = event.album

    return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    let index = self.tableView.indexPathForSelectedRow?.row
    //use the index to know which cell you selected

    //check for your condition here something like
    if isAdmin {
        performSegueWithIdentifier("eventViewControllerSegue", sender: self)
    } else {
        performSegueWithIdentifier("userEventTableViewControllerSegue", sender: self)
    }
}

// Override to support conditional editing of the table view.
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
    // Return false if you do not want item to be editable.
    return true
}


// Override to support editing the table view.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
        // Delete the row from the data source
        events.removeAtIndex(indexPath.row)
        saveEvents()
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
    } else if editingStyle == .Insert {
        // Create new instance of  class, add to the array, and add a new row to the table
    }
}


/*
// Override to support rearranging the table view.
override func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {

}
*/

/*
// Override to support conditional rearranging of the table view.
override func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the item to be re-orderable.
return true
}
*/


// MARK: - Navigation

// preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "eventViewControllerSegue"  {
        let eventDetailViewController = segue.destinationViewController as! EventViewController

        // Get the cell that generated this segue.
        if let selectedEventCell = sender as? EventTableViewCell {
            let indexPath = tableView.indexPathForCell(selectedEventCell)!
            let selectedEvent = events[indexPath.row]
            eventDetailViewController.event = selectedEvent

        }
    } else  if segue.identifier == "userEventTableViewControllerSegue"  {
        let eventDetailViewController = segue.destinationViewController as! UserEventViewController

        // Get the cell that generated this segue.
        if let selectedEventCell = sender as? EventTableViewCell {
            let indexPath = tableView.indexPathForCell(selectedEventCell)!
            let selectedEvent = events[indexPath.row]
            eventDetailViewController.event = selectedEvent

        }
    }
    else if segue.identifier == "AddItem" {
        print("Adding new event.")
    }
}


@IBAction func unwindToMealList(sender: UIStoryboardSegue) {
    if let sourceViewController = sender.sourceViewController as? EventViewController, event = sourceViewController.event {
        if let selectedIndexPath = tableView.indexPathForSelectedRow {
            // Update an existing event.
            events[selectedIndexPath.row] = event
            tableView.reloadRowsAtIndexPaths([selectedIndexPath], withRowAnimation: .None)
        } else {
            // Add a new event.
            let newIndexPath = NSIndexPath(forRow: events.count, inSection: 0)
            events.append(event)
            tableView.insertRowsAtIndexPaths([newIndexPath], withRowAnimation: .Bottom)
        }
        // Save the events.
        saveEvents()
    }
}

// MARK: NSCoding

func saveEvents() {
    let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(events, toFile: Event.ArchiveURL.path!)
    if !isSuccessfulSave {
        print("Failed to save events...")
    }
}

func loadEvents() -> [Event]? {
    return NSKeyedUnarchiver.unarchiveObjectWithFile(Event.ArchiveURL.path!) as? [Event]
}
}

Solution

  • You typically want to find the event related to the row selected. So, you will need to record which row is selected. Introduce a variable called as:

    var currentlySelectedIndex = 0
    

    to your EventTableViewController

    Then change the implementation of didSelectRow delegate method in the same class to-

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    //Record the row selected
    currentlySelectedIndex = indexPath.row
    
    //check for your condition here something like
    if isAdmin {
        performSegueWithIdentifier("eventViewControllerSegue", sender: self)
    } else {
        performSegueWithIdentifier("userEventTableViewControllerSegue", sender: self)
    }
    

    }

    And thirdly, you will need to utilise this selected row index to fetch right event object:

      override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "eventViewControllerSegue"  {
          let eventDetailViewController = segue.destinationViewController as! EventViewController
          //Get the associated event
          eventDetailViewController.event = events[currentlySelectedIndex]
        } else  if segue.identifier == "userEventTableViewControllerSegue"  {
          let eventDetailViewController = segue.destinationViewController as! UserEventViewController
          //Get the associated event
          eventDetailViewController.event = events[currentlySelectedIndex]
        }
        else if segue.identifier == "AddItem" {
          print("Adding new event.")
        }
      }
    

    This will resolve your issues.