Having trouble populating tableView using Firebase/Firestore in iOS - ios

Question

This is my first time working with a cloud database and I'm looking for a little bit of guidance here as I'm relatively new to programming, and Firestore in particular.
I'm trying to get() all of my document data inside of my viewDidLoad and store it inside of a dictionary so that I can use it later in the tableView dataSource methods to populate my tableView Sections and Rows.
I'm working on a gym/workout log app and I inputted some dummy data for Days and Workouts Collections, so my dictionary prints out like this...
dataDict = ["Monday": ["Chest", "Arms"], "Wednsday": ["Legs", "Arms"], "Tuesday": ["Back"]]
But I'm having trouble using this data to populate the fields because if I try to print out the results of dataDict outside of the dateWorkoutRequest function, like inside of my dataSource methods, I get an empty dictionary. Is my tableView.reloadData() in the wrong place? Should I be using a dictionary to parse my data or is that a bad idea?
Here is my data structure and the relevant code...
/users/mi9P3TrLwkQejYo3oDIu/Days/WZ3Q6LDuu1kja5Rc/Workouts/BpLGFREoJNzNQW
var daysArray = [String]()
var dayIdArray = [String]()
var dataDict : [String:[String]] = [:]
//MARK: - viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
vcBackgroundImg()
navConAcc()
picker.delegate = self
picker.dataSource = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellID)
tableView.tableFooterView = UIView()
Auth.auth().addStateDidChangeListener { (auth, user) in
self.userIdRef = user!.uid
self.colRef = Firestore.firestore().collection("/users/\(self.userIdRef)/Days")
self.dateWorkoutRequest()
}
}
func dateWorkoutRequest(){
self.colRef.getDocuments { (snapshot, err) in
if let err = err
{
print("Error getting documents: \(err)");
}
else {
//Appending all Days collection documents with a field of "dow" to daysarray...
for dayDocument in snapshot!.documents {
self.daysArray.append(dayDocument.data()["dow"] as? String ?? "")
self.dayIdArray.append(dayDocument.documentID)
Firestore.firestore().collection("/users/\(self.userIdRef)/Days/\(dayDocument.documentID)/Workouts/").getDocuments { (snapshot, err) in
if let err = err
{
print("Error getting documents: \(err)");
}
else {
//Assigning all Workouts collection documents belonging to selected \(dayDocument.documentID) to dictionary dataDict...
for document in snapshot!.documents {
if self.dataDict[dayDocument.data()["dow"] as? String ?? ""] == nil {
self.dataDict[dayDocument.data()["dow"] as? String ?? ""] = [document.data()["workout"] as? String ?? ""]
} else {
self.dataDict[dayDocument.data()["dow"] as? String ?? ""]?.append(document.data()["workout"] as? String ?? "")
}
print(self.dataDict)
}
}
}
}
self.dayCount = snapshot?.count ?? 0
self.tableView.reloadData()
}
}
}

Answer 1

I would try to put the self.tableView.reloadData() just after the line that you append document in the array.
I think that it's interesting you put DispatchQueue.main.async block in the reloadData too.
Like this:
func dateWorkoutRequest(){
self.colRef.getDocuments { (snapshot, err) in
if let err = err
{
print("Error getting documents: \(err)");
}
else {
//Appending all Days collection documents with a field of "dow" to daysarray...
for dayDocument in snapshot!.documents {
self.daysArray.append(dayDocument.data()["dow"] as? String ?? "")
self.dayIdArray.append(dayDocument.documentID)
Firestore.firestore().collection("/users/\(self.userIdRef)/Days/\(dayDocument.documentID)/Workouts/").getDocuments { (snapshot, err) in
if let err = err
{
print("Error getting documents: \(err)");
}
else {
//Assigning all Workouts collection documents belonging to selected \(dayDocument.documentID) to dictionary dataDict...
for document in snapshot!.documents {
if self.dataDict[dayDocument.data()["dow"] as? String ?? ""] == nil {
self.dataDict[dayDocument.data()["dow"] as? String ?? ""] = [document.data()["workout"] as? String ?? ""]
} else {
self.dataDict[dayDocument.data()["dow"] as? String ?? ""]?.append(document.data()["workout"] as? String ?? "")
}
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
}
}
}
self.dayCount = snapshot?.count ?? 0
}
}
}