My NSDictionary is becoming nil inside my IBAction - ios

Question

I have a tableview that presents events that a user creates. When you click on one of them it takes you to a different page that presents the details of the event.
I'm using Firebase and passing the postID from the tableview to the detailed view and all the information is being passed correctly in an NSDictionary.
However, when I try to access the NSDictionary out of the viewDidLoad and in an IBAction it tells me that the NSDictionary is nil. When I check in the viewDidLoad it is not nil.
I'm very new to programming and learning along the way but I've been stuck on this for a while now and have no idea whats wrong or how I can fix it
this is my code
import UIKit
import Firebase
class BeehiveViewViewController: UIViewController {
#IBOutlet weak var eventImage: UIImageView!
#IBOutlet weak var eventName: UILabel!
#IBOutlet weak var location: UILabel!
#IBOutlet weak var eventDate: UILabel!
#IBOutlet weak var eventHost: UILabel!
#IBOutlet weak var members: UILabel!
#IBOutlet weak var joinButton: roundButton!
var beehiveID: NSDictionary?
var ref = Database.database().reference()
override func viewDidLoad() {
super.viewDidLoad()
view.setGradientBackground(colourOne: primaryColor, colourTwo: secondaryColor)
let uid = Auth.auth().currentUser?.uid
ref.child("users").child(uid!).child(self.beehiveID?["pid"] as! String).observe(.value) { (snapshot) in
let uid = self.beehiveID!["pid"] as! String
self.beehiveID = snapshot.value as? NSDictionary
self.beehiveID?.setValue(uid, forKey: "pid")
}
let imageURL = self.beehiveID!["imageDownloadURL"] as! String
let url = URL(string: imageURL)
DispatchQueue.global(qos: .background).async {
let data = NSData(contentsOf: url!)
DispatchQueue.main.async {
self.eventImage.image = UIImage(data: data! as Data)
}
}
self.eventName.text = self.beehiveID?["eventName"] as? String
self.eventDate.text = self.beehiveID?["eventDate"] as? String
self.eventHost.text = self.beehiveID?["beehiveHost"] as? String
self.location.text = self.beehiveID?["location"] as? String
let uidd = Auth.auth().currentUser?.uid
Database.database().reference().child("users").child(uidd!).child("Posts").child(self.beehiveID?["pid"] as! String).child("Members").observe(.value) { (snapshot) in
let memberCount = snapshot.childrenCount
self.members.text = "\(memberCount)"
}
let userID = Auth.auth().currentUser?.uid
Database.database().reference().child("users").child(userID!).child("Posts").child(self.beehiveID?["pid"] as! String).observe(.value) { (snapshot) in
print(snapshot)
if (snapshot.exists()){
self.joinButton.setTitle("Remove Beehive", for: .normal)
}
else{
self.joinButton.setTitle("Join Beehive", for: .normal)
}
}
}
#IBAction func buttonPressed(_ sender: Any) {
if joinButton.titleLabel?.text == "Remove Beehive"{
let uid = Auth.auth().currentUser?.uid
let dbref = ref.child("users").child(uid!).child("Posts").child(beehiveID?["pid"] as! String)
//error is the line above that beehiveID?["pid"] is nil
dbref.removeValue()
navigationController?.popViewController(animated: true)
}
if joinButton.titleLabel?.text == "Join Beehive"{
let uid = Auth.auth().currentUser?.uid
let dbref = Database.database().reference().child("users").child(uid!).child("Posts").child("Members")
Database.database().reference().child("users").child(uid!).child("Name").observe(.value) { (nameSnapshot) in
let memberName = nameSnapshot.value as! String
let userObject = [memberName: uid]
dbref.updateChildValues(userObject as! [AnyHashable : String])
}
}
}
}

Answer 1

I assume that you're passing beeHive's value from the previous controller as you haven't initialised or got the values of it anywhere:-
Try having a breakpoint right before the end of viewDidLoad to double-check if the dictionary isn't nil at the block
self.beehiveID = snapshot.value as? NSDictionary
Try using a check to see if the snapshot's value is nil using 'if let' or 'guard' as you could possibly just be assigning a nil value to the NSDictionary. Also, since you're using optionals for assigning each value, it doesn't return an exception but just keeps assigning the nil value to every property
Do try this and let me know. Glad to help!