I'm having trouble with loading the table view. The moment I call self.messagesTable.reloadData() my local tableView does not reload the data deleted from a external Firebase server.
These two are my handlers for the observer:
fileprivate var _refHandle: FIRDatabaseHandle!
fileprivate var _refHandleDel: FIRDatabaseHandle!
Outlet
@IBOutlet weak var messagesTable: UITableView!
Code in FCViewController:
var ref: FIRDatabaseReference!
var messages: [FIRDataSnapshot]! = []
var messageClass = [Message]()
var messageDictionary = [String: Message]()
func configureDatabase() {
// configure database to sync messages and connect it to the data base starting at "/"
ref = FIRDatabase.database().reference()
// create a listener on what happend on the database
_refHandle = ref.child("messages").observe(.childAdded) { (snapshot: FIRDataSnapshot!) in
self.messages.append(snapshot)
// Animate and scroll the new message loaded
self.messagesTable.insertRows(at: [IndexPath(row: self.messages.count - 1, section: 0)], with: .automatic)
self.scrollToBottomMessage()
}
_refHandleDel = ref.child("messages").observe(.childRemoved, with: { (snapshot: FIRDataSnapshot!) in
self.messageDictionary.removeValue(forKey: snapshot.key)
// MY PROBLEM IS HERE: The table does not load properly and does not reloadData from the server after deleting the snapshot.key
self.messagesTable.reloadData()
}, withCancel: nil)
}
deinit {
// set up what needs to be deinitialized when view is no longer being used
// we remove the observer that is all the time checking for updates in the .observer handler
ref.child("messages").removeObserver(withHandle: _refHandle)
ref.child("messages").removeObserver(withHandle: _refHandleDel)
// we also remove the listener for auth changes when the user registers
FIRAuth.auth()?.removeStateDidChangeListener(_authHandle)
}
Scroll Messages Function also inside the FCViewController:
func scrollToBottomMessage() {
if messages.count == 0 { return }
let bottomMessageIndex = IndexPath(row: messagesTable.numberOfRows(inSection: 0) - 1, section: 0)
messagesTable.scrollToRow(at: bottomMessageIndex, at: .bottom, animated: true)
}
Message Class Object in a separate .swift file courtesy of @Jay
class Message: NSObject {
class MessageClass {
var key = ""
var name = ""
var text = ""
var timestamp = ""
}
var messagesArray = [MessageClass]()
let ref = FIRDatabase.database().reference()
func readInAllMessages() {
let messagesRef = ref.child("messages")
messagesRef.observeSingleEvent(of: .value, with: { snapshot in
for child in snapshot.children {
let snap = child as! FIRDataSnapshot
let msg = self.snapToMsgClass(child: snap)
self.messagesArray.append(msg)
}
})
}
func addRemoveObserver() {
let messagesRef = ref.child("messages")
messagesRef.observe(.childRemoved, with: { snapshot in
let keyToRemove = snapshot.key
if let i = self.messagesArray.index(where: { $0.key == keyToRemove }) {
self.messagesArray.remove(at: i)
}
})
}
func snapToMsgClass(child: FIRDataSnapshot) -> MessageClass {
let dict = child.value as! [String:Any]
let name = dict["name"] as! String
let msg = MessageClass()
msg.name = name
msg.key = child.key
return msg
}
}
