tableview doesn't refresh deleted data - ios

Question

My table view does not refresh. it keep the old values of deleted data
and can show new added values.
it only refresh(remove deleted values) when i close the app and open it again.
here is my code
private func observeChannels() {
let userEmail = Auth.auth().currentUser?.email
channelRefHandle = channelRef.observe(.childChanged, with: { (snapshot) -> Void in
let channelData = snapshot.value as! Dictionary<String, AnyObject>
let id = snapshot.key
let groupimage = channelData["groupImage"] as? String!
let descc = channelData["desc"] as? String!
let groupCountvar = channelData["Members"]?.count
let groupTasksVar = channelData["Tasks"]?.count
if let name = channelData["name"] as! String!, name.characters.count > 0 {
//members snapshot
if let childSnapshot = snapshot.childSnapshot(forPath: "Members") as? DataSnapshot{
if let membersDictionary = childSnapshot.value as? [String:AnyObject] , membersDictionary.count > 0{
for membersDictionary in membersDictionary {
if userEmail == membersDictionary.value as? String {
self.groups.append(Group(id: id,name: name, createdBy: (userEmail)!, desc: (descc)!, groupImage: (groupimage)!, groupCount: ("\(groupCountvar!)") , groupTasksCount: ("\(groupCountvar!)")))
print(membersDictionary.value)
}
}
}
self.tableView.reloadData()
}}else {
print("Error!")
self.tableView.reloadData()
}
})}
datasource / delegate
override func numberOfSections(in tableView: UITableView) -> Int {
return 2 }
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if let currentSection: Section = Section(rawValue: section) {
switch currentSection {
case .createNewChannelSection:
return 0
case .currentChannelsSection:
return groups.count
}
} else {
return 0 }
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 75.0 }
//tableView
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ExistingChannel", for: indexPath) as! GroupTableViewCell
if (indexPath as NSIndexPath).section == Section.currentChannelsSection.rawValue {
cell.goupName?.text = groups[(indexPath as NSIndexPath).row].name
cell.groupDesc?.text = groups[(indexPath as NSIndexPath).row].desc
cell.groupimg?.image = UIImage(named: groups[(indexPath as NSIndexPath).row].groupImage)
cell.numbMembLbl?.text = groups[(indexPath as NSIndexPath).row].groupCount
cell.taskNumbLbl?.text = groups[(indexPath as NSIndexPath).row].groupTasksCount
}
return cell }
// MARK: UITableViewDelegate
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if (indexPath as NSIndexPath).section == Section.currentChannelsSection.rawValue {
let channel = groups[(indexPath as NSIndexPath).row]
self.performSegue(withIdentifier: "ShowChannel", sender: channel)
} }
this is my table view i dont know why the deleted/removed doesn't observe.

Answer 1

You are observing the node for .childChanged events only.
That means the code in the closure will only fire if a child is changed.
From the documentation
FIRDataEventTypeChildChanged - Listen for changes to the items in a
list. This event is triggered any time a child node is modified. This
includes any modifications to descendants of the child node. The
snapshot passed to the event listener contains the updated data for
the child.
So that means the code in your closure will only be called when a child is changed, and will not be called when a child is added or deleted.
You need to add additional observers for .childAdded events and .childRemoved events to handle those cases. When you receive a childAdded event, add that snapshot data to your array and likewise when you receive a childRemoved event, remove it from the array.
Remember to reload your table view in all cases so the UI updates with the fresh data.
I personally would change this line to make it more readable
for membersDictionary in membersDictionary {
to
for member in membersDictionary {
but that's just a style thing.

Answer 2

Try using this for reloading tableView
DispatchQueue.main.async {
self.tableView.reloadData()
}
This will help.

Answer 3

you need this :
func tableView(_ tableView: UITableView, commit editingStyle:
UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
print("Deleted")
self.yourArrayName.remove(at: indexPath.row)
self.tableView.deleteRows(at: [indexPath], with: .automatic)
}
}
It'll do the job.