How can I expand inner scope value in Swift - ios

Question

I started develop not long. So I have problem in my code. I want return data.count in TableView function. But I can't get value of data: [DataGroup] in db.collection(). It isn't have value out of db.collection() scope. So how can I get data from that scope?
class RecordGroupViewController: UIViewController, UITableViewDataSource {
let db = Firestore.firestore()
var data: [DataGroup] = []
override func viewDidLoad() {
super.viewDidLoad()
fetchDataGroup()
}
func fetchDataGroup() {
db.collection("data").getDocuments() { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for document in querySnapshot!.documents {
do {
let docuData = try JSONSerialization.data(withJSONObject: document.data(), options: [])
let decoder = JSONDecoder()
let groupData: DataGroup = try decoder.decode(DataGroup.self, from: data)
self.data.append(groupData)
} catch let error {
print("---> error: \(error.localizedDescription)")
}
}
}
}
print("\(self.recordGroups.count)")
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
return UITableViewCell()
}
}

Answer 1

From what I understood of your question, you want to access your data variable's count.
You can do so from anywhere in your code using self.data.count
However, if you want your tableView to use this new value :
Link your tableview to your controller using an IBOutlet (or create a reference to it if you instantiate it programmatically)
After you have appended your data with the new data, call self.yourTableViewReference.reloadData(), this will make the tableView call your dataSource method numberOfRowsInSection with the newly appended data.