Swift: Cannot put my value into label (optional issue) - ios

Question

I have my value from Firebase but Swift doesn't want to put it in my label.
Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value
To summarize, my database look like that:
Firebase database
I've created a standard model call ServiceModel:
import Foundation
class ServiceModel {
var name: String?
var category: String?
var pricing: String?
init(name: String?, category: String?, pricing: String?){
self.name = name
self.category = category
self.pricing = pricing
}
}
I want to display this values into a TableView, so I've created a custom cell like this (very standard too):
import UIKit
class SubscriptionTableViewCell: UITableViewCell {
#IBOutlet weak var imageService: UIImageView!
#IBOutlet weak var labelName: UILabel!
#IBOutlet weak var labelCategory: UILabel!
#IBOutlet weak var labelPricing: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
And now, here is the controller of my view:
import UIKit
import FirebaseDatabase
class SecondViewController: UIViewController,UITableViewDelegate, UITableViewDataSource {
var refServices:DatabaseReference!
#IBOutlet weak var ListSub: UITableView!
var serviceList = [ServiceModel]()
var databaseHandle:DatabaseHandle?
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return serviceList.count
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SubCell", for: indexPath) as! SubscriptionTableViewCell
let service: ServiceModel
service = serviceList[indexPath.row]
//cell.imageService.image = UIImage(named: service.name! + ".png")
cell.labelName?.text = service.name //ERROR HERE
cell.labelCategory?.text = service.category
cell.labelPricing?.text = service.pricing
return cell
}
override func viewDidLoad() {
super.viewDidLoad()
ListSub.delegate = self
ListSub.dataSource = self
refServices = Database.database().reference().child("Categories");
refServices.observe(DataEventType.value, with: { (snapshot) in
if snapshot.childrenCount > 0 {
self.serviceList.removeAll()
for services in snapshot.children.allObjects as! [DataSnapshot] {
let serviceObject = services.value as? [String: AnyObject]
let serviceName = serviceObject?["Name"]
let serviceCategory = serviceObject?["Category"]
let servicePricing = serviceObject?["Pricing"]
let service = ServiceModel(name: serviceName as! String?, category: serviceCategory as! String?, pricing: servicePricing as! String?)
self.serviceList.append(service)
}
self.ListSub.reloadData()
}
})
}
When I launch this view, I have the error mentioned earlier.
When I debug, I see that I have the right values in service.name, service.category and service.pricing
It seems that I don't correctly handle Optional values, but I cannot see what is wrong.
Thanks for your help.

Answer 1

Potential lines to be crashed in case of optional unwrapping is this line
refServices = Database.database().reference().child("Categories");
refServices.observe(DataEventType.value, with: { (snapshot) in
Try to pur breakpoint and check if refServices is initialised properly or make ti to be optional not using !
Hope this help
Ps. please remove ; out of your Swift code :P

Answer 2

Use this code:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SubCell", for: indexPath) as! SubscriptionTableViewCell
let service = serviceList[indexPath.row]
// If you sure that you have to display all the info use this code
if let name = service.name, let category = service.category, let price = service.pricing {
cell.labelName.text = name
// set other data also here....
}
// If you know any value may be empty or not exists then use this code.
if let name = service.name {
cell.labelName.text = name
}
if let category = service.category {
cell.labelCategory.text = service
}
if let pricing = service.pricing {
cell.labelPricing.text = pricing
}
return cell
}

Answer 3

Did you register your custom UITableViewCell with your tableView? Put this line into the init() function of your ViewController:
ListSub.register(SubscriptionTableViewCell.classForCoder(), forCellReuseIdentifier: "SubCell")

Answer 4

If you debug this function, what did you see for your service
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SubCell", for: indexPath) as! SubscriptionTableViewCell
let service: ServiceModel
//Put a breakpoint here
service = serviceList[indexPath.row]
//Put a breakpoint here
//cell.imageService.image = UIImage(named: service.name! + ".png")
cell.labelName?.text = service.name
cell.labelCategory?.text = service.category
cell.labelPricing?.text = service.pricing
return cell
}