Index out of range error keeps crashing my app - ios

Question

I have a tableview loading data from firebase database. When i open my app the data does not populate. it crashes and throws the error index out of range. I am fairly new to xcode and would appreciate the help. i have been given recommendations on how to fix my code with regards to having multiple arrays but everyone that advices forget i'm new and does realize that i am pulling imageurls into my tableview too and dont know how to adopt their recommendations into my code. if i could get help getting passed this error that would be awesome.
import UIKit
import FirebaseAuth
import FirebaseDatabase
class EventsViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var eventsRef: DatabaseReference?
var eventsDatabaseHandle:DatabaseHandle?
var eventsTitles = [String]()
var eventTimestamps = [String]()
var eventsLocations = [String]()
var eventsImages = [UIImage]()
#IBOutlet weak var addEventsButton: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
adminAuth()
eventsRef = Database.database().reference()
tableView.reloadData()
tableView.transform = CGAffineTransform(rotationAngle: -CGFloat.pi)
tableView.delegate = self
tableView.dataSource = self
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { (snaphot) in
let eventPost = snaphot.value as! [String: Any]
self.eventTimestamps.append(eventPost["eventdate"] as! String)
self.eventsTitles.append(eventPost["eventtitle"] as! String)
self.eventsLocations.append(eventPost["eventlocation"] as! String)
let task = URLSession.shared.dataTask(with: URL(string: eventPost["ImageUrl"] as! String)!) {(data, response, error) in
if let image: UIImage = UIImage(data: data!) {
self.eventsImages.append(image)
}
}
task.resume()
self.tableView.reloadData()
})
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return eventsTitles.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events") as! EventsTableViewCell
// let image = eventsImages[indexPath.row]
cell.flyerImages.image? = eventsImages[indexPath.row] **<- index out of range**
cell.eventTitle.text! = eventsTitles[indexPath.row]
cell.eventDate.text! = eventTimestamps[indexPath.row]
cell.eventLocation.text! = eventsLocations[indexPath.row]
cell.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
return cell
}
func adminAuth() {
if (Auth.auth().currentUser!.displayName != "Neil Leon") {
self.addEventsButton.tintColor = UIColor.clear
self.addEventsButton.isEnabled = false
}
else{
self.addEventsButton.isEnabled = true
}
}
}``````

Answer 1

At the moment reloadData is called the image array is empty and causes the crash
Use a custom struct and reload the table view after the image data has been received
struct Event {
let title, timestamp, location : String
var image : UIImage?
}
var events = [Event]()
...
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { (snaphot) in
let eventPost = snaphot.value as! [String: Any]
let event = Event(title: eventPost["eventtitle"] as! String,
timestamp: eventPost["eventdate"] as! String,
location: eventPost["eventlocation"] as! String,
image: nil)
let task = URLSession.shared.dataTask(with: URL(string: eventPost["ImageUrl"] as! String)!) { data, _, error in
if let error = error {
print(error)
} else {
event.image = UIImage(data: data!)
DispatchQueue.main.async {
self.events.append(event)
self.tableView.reloadData()
}
}
}
task.resume()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return events.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events", for: indexPath) as! EventsTableViewCell
let event = events[indexPath.row]
cell.flyerImages.image = event.image
cell.eventTitle.text = event.title
cell.eventDate.text = event.timestamp
cell.eventLocation.text = event.location
cell.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
return cell
}