TableView not displaying data from Firebase Database - ios

Question

I am building an app which uses Firebase's database service. I am trying to load the data into a table view but I am unable to do so. I can't seem to figure out what's going wrong. The code is also not giving me any errors. I've checked the database permissions on Firebase and they seem to be good. Here's my code:
import UIKit
import Firebase
struct postStruct {
let word : String!
let wordType : String!
}
class sentenceBuilderViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var wordSearchBar: UISearchBar!
#IBOutlet weak var wordsTableView: UITableView!
var posts = [postStruct]()
override func viewDidLoad() {
wordsTableView.reloadData()
getWordsFromDatabase()
super.viewDidLoad()
wordsTableView.delegate = self
wordsTableView.dataSource = self
}
func getWordsFromDatabase() {
let databaseRef = Database.database().reference()
databaseRef.child("wordList").queryOrderedByKey().observeSingleEvent(of: .childAdded, with: {
snapshot in
let word = (snapshot.value as? NSDictionary)!["word"] as? String
let wordType = (snapshot.value as? NSDictionary
)!["wordType"] as? String
self.posts.insert(postStruct(word: word, wordType: wordType), at: 0)
})
wordsTableView.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = wordsTableView.dequeueReusableCell(withIdentifier: "Cell")
let wordLabel = cell?.viewWithTag(1) as! UILabel
wordLabel.text = posts[indexPath.row].word
let wordTypeLabel = cell?.viewWithTag(2) as! UILabel
wordTypeLabel.text = posts[indexPath.row].wordType
return cell!
}
}
Any help and inputs would be appreciated! Thanks!

Answer 1

The problem is that you are just observing a single event here:
databaseRef.child("wordList").queryOrderedByKey().observeSingleEvent(of: .childAdded, with: {
snapshot in
What this does is that it justs goes through your database and once it finds any child, it displays that one without going further. What you need to do is change it to observe like this:
func getAllWordsFromDatabase() {
let databaseRef = Database.database().reference()
databaseRef.child("wordList").queryOrderedByKey().observe(.childAdded, with: {
snapshot in
let word = (snapshot.value as? NSDictionary)!["word"] as? String
let wordType = (snapshot.value as? NSDictionary)!["wordType"] as? String
self.posts.append(postStruct(word: word, wordType: wordType))
DispatchQueue.main.async {
self.wordsTableView.reloadData()
}
})
}
Try implementing this and it should work.

Answer 2

Move the "getWordsFromDatabase()" line in "viewDidLoad" function to AFTER you assign the delegate and data source, like this:
override func viewDidLoad() {
super.viewDidLoad()
wordsTableView.delegate = self
wordsTableView.dataSource = self
getWordsFromDatabase()
}
Also you can try to add a "reloadData()" method in the databaseRef block on the main queue, like this:
let databaseRef = Database.database().reference()
databaseRef.child("wordList").queryOrderedByKey().observeSingleEvent(of: .childAdded, with: {
snapshot in
let word = (snapshot.value as? NSDictionary)!["word"] as? String
let wordType = (snapshot.value as? NSDictionary
)!["wordType"] as? String
self.posts.insert(postStruct(word: word, wordType: wordType), at: 0)
DispatchQueue.main.async {
wordsTableView.reloadData()
}
})