Swift Firebase UITableViewCell loads before Data to populate cell is available - ios

Question

I am pushing data which is an array of strings to a tableview controller. These strings are "uid's" which are users in my database. With this array I make a call to firebase to extract all users and then do a match to the uid's. I am getting the correct data, yet I print out everything to make sure when the data is available and the data is available only after the tableview cell loads which causes the data to be nil causing a crash or just empty data. How can I make the data load first and then the cell so the data is available for display?
I've created functions for the data and now I have it in my viewDidLoad. Also, you'll see I have tried adding the firebase call into the Cell setup but of course that does not work.
Array of strings
var data = [String]()
viewDidLoad
override func viewDidLoad() {
super.viewDidLoad()
Database.database().reference().child("Businesses").observe(.value, with: { snapshot in
if snapshot.exists() {
self.businessUID = snapshot.value as? NSDictionary
if let dict = snapshot.value as? NSDictionary {
for item in dict {
let json = JSON(item.value)
let businessUid = json["uid"].stringValue
for uid in self.data {
if uid == businessUid {
let customerValue = self.businessUID?[uid]
self.businessDictionary = customerValue as! NSDictionary
print(self.businessDictionary)
print("Just printed the business dictionary")
}
}
}
}
} else {
print("does not exist")
}
})
}
Tableview Cell
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CustomerViewsSelectedBusinessesCell
print(self.businessDictionary)
print("Print the dictionary here to check the values")
let businessValues = self.businessDictionary
let uid = self.data.description
print(businessValues)
print("printed the business values")
if let dict = businessValues {
for item in dict {
let json = JSON(item.value)
let businessUid = json["uid"].stringValue
for uid in self.data {
if uid == businessUid {
let customerValue = self.businessUID?[uid]
self.businessData = customerValue as? NSDictionary
print(self.businessData)
print("Printing matching the uid values")
}
}
}
}
cell.businessName.text = businessData?["businessName"] as? String
cell.businessStreet.text = businessData?["businessStreet"] as? String
cell.businessCity.text = businessData?["businessCity"] as? String
cell.businessState.text = businessData?["businessState"] as? String
let businessProfilePicture = businessData?["profPicString"] as? String
if (businessProfilePicture!.characters.count) > 0 {
let url = URL(string: (businessProfilePicture!))
DispatchQueue.global().async {
let data = try? Data(contentsOf: url!)
DispatchQueue.main.async {
let image = UIImage(data: data!)?.potter_circle
cell.profileImage.contentMode = UIView.ContentMode.scaleAspectFill
cell.profileImage.image = image
}
}
} else {
let image = UIImage(named: "default")?.potter_circle
cell.profileImage.contentMode = UIView.ContentMode.scaleAspectFill
cell.profileImage.image = image
}
return cell
}

Answer 1

Here is my solution. Got it to work. Appened and used "usersArray" to get and display the data.
var data = [String]()
var usersArray = [NSDictionary?]()
override func viewDidLoad() {
super.viewDidLoad()
Database.database().reference().child("Businesses").observe(.value, with: { snapshot in
if snapshot.exists() {
self.businessUID = snapshot.value as? NSDictionary
if let dict = snapshot.value as? NSDictionary {
for item in dict {
let json = JSON(item.value)
let businessUid = json["uid"].stringValue
for uid in self.data {
if uid == businessUid {
let customerValue = self.businessUID?[uid]
self.usersArray.append(customerValue as! NSDictionary)
self.followUsersTableView.reloadData()
}
}
}
}
} else {
print("does not exist")
}
})
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.usersArray.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CustomerViewsSelectedBusinessesCell
let user : NSDictionary?
user = self.usersArray[indexPath.row]
cell.businessName.text = String(user?["businessName"] as! String)
cell.businessStreet.text = String(user?["businessStreet"] as! String)
cell.businessCity.text = String(user?["businessCity"] as! String)
cell.businessState.text = String(user?["businessState"] as! String)
let businessProfilePicture = String(user?["profPicString"] as! String)
if (businessProfilePicture.characters.count) > 0 {
let url = URL(string: (businessProfilePicture))
DispatchQueue.global().async {
let data = try? Data(contentsOf: url!)
DispatchQueue.main.async {
let image = UIImage(data: data!)?.potter_circle
cell.profileImage.contentMode = UIView.ContentMode.scaleAspectFill
cell.profileImage.image = image
}
}
} else {
let image = UIImage(named: "default")?.potter_circle
cell.profileImage.contentMode = UIView.ContentMode.scaleAspectFill
cell.profileImage.image = image
}
return cell
}