I am trying to load information to a tableView, and I get an exception because some information in the cell isn't initialized when I cast to it. and this is my code :
The code for the view containing the tableView:
private func populateActiveChats()
{
let loggedOnUserID = Auth.auth().currentUser?.uid
let ref = Constants.refs.databaseChatsLite.child(loggedOnUserID!)
ref.observe(.value, with:
{ (snapshot) in
for child in snapshot.children.allObjects as! [DataSnapshot]
{
if (self.chatsDictionary.keys.contains(child.key) == false)
{
let chatValueDictionary = child.value as? NSDictionary
self.AddChatToCollections(chatAsDictionary: chatValueDictionary)
self.DispatchQueueFunc()
}
}
})
}
func AddChatToCollections(chatAsDictionary: NSDictionary!)
{
if chatAsDictionary == nil
{
return
}
let contactName =
chatAsDictionary[Constants.Chat.ChatRoomsLite.CONTACT_NAME] as! String
let newMsgs = chatAsDictionary[Constants.Chat.ChatRoomsLite.NUM_OF_UNREAD_MSGS] as! Int
let contactID = chatAsDictionary[Constants.Chat.ChatRoomsLite.CONTACT_ID] as! String
let chatToAdd = PrivateChatLiteObject(chattingWith: contactName, ContactID: contactID, unreadMessages: newMsgs, LastMSG: "")
chatsDictionary[contactID] = chatToAdd
chatsIndex.append(contactID)
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell = ChatsTableView.dequeueReusableCell(withIdentifier: "chat_room_cell", for: indexPath) as! PrivateChatUITableViewCell
let indexedID = chatsIndex[indexPath.row]
cell.ContactName.text = chatsDictionary[indexedID]?.GetContactName()
cell.ContactID = chatsDictionary[indexedID]?.GetContactID()
return cell
}
And in my PrivateChatUITableViewCell:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell = ChatsTableView.dequeueReusableCell(withIdentifier: "chat_room_cell", for: indexPath) as! PrivateChatUITableViewCell
//cell.ContactImageView = UIImageView.loadImageUsingUrlString(contactImg)
let indexedID = chatsIndex[indexPath.row]
cell.ContactName.text = chatsDictionary[indexedID]?.GetContactName()
cell.ContactID = chatsDictionary[indexedID]?.GetContactID()
//cell.PopulateCell()
return cell
}
public func PopulateCell()
{
let currentID = Constants.refs.currentUserInformation?.uid
Constants.refs.databaseChatsLite.child(currentID!).child(ContactID!).observeSingleEvent(of: .value, with: {(snapshot) in ...})
}
The code crashes when it reaches the Constants.refs.databaseChatsLite.child(currentID!).child(ContactID!)
line because ContactID isn't initialized.
This is being called when casting cell to PrivateChatUITableViewCell
I haven't changed my code and this used to work, so I am not sure what changed or what I am doing wrong. Where should my code be fixed?
Related
I'm trying to hide cells from a UITableView. My codes are below.
When I open the app I see empty rows in my TableViewas you can see here
How can I hide or remove(not delete) empty cells from UITableView?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! FeedTableViewCell
let row = self.items[indexPath.row]
cell.lblTitle.text = row.title
cell.isHidden = !checkCurrentUser(email: row.email)
return cell
}
I added filtered array but then I take different error like this. My new codes are below. How can I solve this problem?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! FeedTableViewCell
let row = self.items[indexPath.row]
self.items = self.items.filter{checkCurrentUser(email: $0.email)}
cell.lblTitle.text = row.title
//cell.isHidden = !checkCurrentUser(email: row.email)
return cell
}
Whole codes are below
import UIKit
import Firebase
class OyuncularVC: UIViewController, UITableViewDelegate, UITableViewDataSource {
var items = [ItemModel]()
#IBOutlet weak var tblView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tblView.tableFooterView = UITableViewHeaderFooterView()
retrieveItems()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! FeedTableViewCell
let row = self.items[indexPath.row]
self.items = self.items.filter{checkCurrentUser(email: $0.email)} //bunu ekledim siliceksem bunu silicem aga
cell.lblTitle.text = row.title
//cell.isHidden = !checkCurrentUser(email: row.email)
return cell
}
/* Retriev Items */
func retrieveItems() {
DataService.dataService.ITEM_REF.observe(.value, with: { (snapshot: DataSnapshot?) in
if let snapshots = snapshot?.children.allObjects as? [DataSnapshot] {
self.items.removeAll()
print(snapshots.count)
for snap in snapshots {
if let postDic = snap.value as? Dictionary<String, AnyObject> {
let itemModel = ItemModel(key: snap.key, dictionary: postDic)
print(itemModel)
self.items.insert(itemModel, at: 0)
}
}
self.tblView.reloadData()
}
})
}
func checkCurrentUser(email: String) -> Bool {
let currentUser = Auth.auth().currentUser
return email == currentUser?.email
}
}
}
If you want to display only the emails of the current user what don't you filter the items in the database (applying a predicate) which is the most efficient way.
Or filter the items in the for snap in snapshots loop.
However if you want to keep the entire data set declare a second array
var items = [ItemModel]()
var filteredItems = [ItemModel]()
and replace
for snap in snapshots {
if let postDic = snap.value as? Dictionary<String, AnyObject> {
let itemModel = ItemModel(key: snap.key, dictionary: postDic)
print(itemModel)
self.items.insert(itemModel, at: 0)
}
}
with the following it performs the check in the loop
let currentUser = Auth.auth().currentUser
self.filteredItems.removeAll()
for snap in snapshots {
if let postDic = snap.value as? Dictionary<String, AnyObject> {
let itemModel = ItemModel(key: snap.key, dictionary: postDic)
print(itemModel)
self.items.insert(itemModel, at: 0)
if itemModel.email == currentUser?.email {
self.filteredItems.insert(itemModel, at: 0)
}
}
}
And replace also the two data source methods with
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return filteredItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! FeedTableViewCell
let row = self.filteredItems[indexPath.row]
cell.lblTitle.text = row.title
return cell
}
And delete the method checkCurrentUser
I want to connect my TableView to what I query from Firestore. The query works, but I can't get the TableView to show the content. Right now its just a blank tableView. The TableViewCell file also has no issues, since it worked before without the firebase implementation (The Cell is registered correctly).
I suspect that the issue is in cellForRowAt and tried played around in there, but couldn't get anything to work.
Can you find the issue?
import UIKit
import Firebase
class popularViewController: UIViewController, UITableViewDelegate, UITableViewDataSource{
#IBOutlet var table: UITableView!
var texttt = [TextPost]()
override func viewDidLoad() {
super.viewDidLoad()
gettingPosts()
table.register(textTableViewCell.nib(), forCellReuseIdentifier: textTableViewCell.identifier)
table.delegate = self
table.dataSource = self
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
gettingPosts()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let alle = models.count + texttt.count
return alle
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: textTableViewCell.identifier, for: indexPath) as! textTableViewCell
cell.configure(with: texttt[indexPath.row])
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 300
}
func gettingPosts(){
let db = Firestore.firestore()
let postsRef = db.collection("posts")
postsRef.addSnapshotListener { (querySnapshot, error) in
guard let snapshot = querySnapshot else {
print("Error fetching snapshots: \(error!)")
return
}
snapshot.documentChanges.forEach { diff in
if (diff.type == .added){
let data = diff.document.data()
let Name = data["username"] as! String
let text = data["description"] as! String
let likes = data["likes"] as! Int
let typ = data["postType"] as! Int
let pfp = data["profileImage"] as! String
let uid = data["uid"] as! String
let pic = data["picture"]
let time = data["time"] as! String
if typ == 0{ // Text post
let dasDing = TextPost(numberOfComments: 0, username: Name, timestampName: time, userImageName: pfp, textName: text)
self.texttt.append(dasDing)
}
}
}
}
}
}
struct TextPost {
let numberOfComments: Int
let username: String
let timestampName: String
let userImageName: String
let textName: String
}
You need to reload data once you get data from firebase
func gettingPosts(){
let db = Firestore.firestore()
let postsRef = db.collection("posts")
postsRef.addSnapshotListener { (querySnapshot, error) in
guard let snapshot = querySnapshot else {
print("Error fetching snapshots: \(error!)")
return
}
snapshot.documentChanges.forEach { diff in
if (diff.type == .added){
let data = diff.document.data()
let Name = data["username"] as! String
let text = data["description"] as! String
let likes = data["likes"] as! Int
let typ = data["postType"] as! Int
let pfp = data["profileImage"] as! String
let uid = data["uid"] as! String
let pic = data["picture"]
let time = data["time"] as! String
if typ == 0{ // Text post
let dasDing = TextPost(numberOfComments: 0, username: Name, timestampName: time, userImageName: pfp, textName: text)
self.texttt.append(dasDing)
}
}
}
DispatchQueue.main.async {
tableView.reloadData()
}
}
}
I have a function that observes data from my Firebase database. This data will be inserted in an array, so it can be send to my tableviewcell Viewcontroller. All the data will be put correct in the tabelviewcell, but I have a problem when I update my Firebase database. Everytime I change a value in the database it will immediately update my tableView even when my function is not called. I am not sure what I am doing wrong and how to prevent this.
This is my function observe:
Database.database().reference().child("posts").child("\(postId)").child("comments").observe(.value, with: { snapshot in
if let snapshots = snapshot.children.allObjects as? [DataSnapshot] {
for snap in snapshots {
if let postDict = snap.value as? Dictionary<String, AnyObject> {
let key = snap.key
let post = Comment.transformComment(dict: postDict)
self.comments.insert(post, at: 0)
self.tableView.reloadData()
}
}
}
})
Array:
var comments: [Comment] = []
extension Comment {
static func transformComment(dict: [String: Any]) -> Comment {
let comment = Comment()
comment.commentText = dict["commentText"] as? String
comment.uid = dict["uid"] as? String
comment.timestamp = dict["timestamp"] as? Int
comment.likeCount = dict["likeCount"] as? Int
comment.childByAutoId = dict["childByAutoId"] as? String
comment.id = dict["postId"] as? String
return comment
}
}
Tablevieww Functions:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if comments.count == 0 {
self.tableView.setEmptyMessage("No comments yet!")
} else {
self.tableView.restore()
}
return comments.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Comment", for: indexPath) as! CommentTableViewCell
let comment = comments[indexPath.row]
cell.comment = comment
cell.delegate = self
return cell
}
To listen once replace
.child("comments").observe(.value, with: { snapshot in
With
.child("comments").observeSingleEvent(of: .value) { snapshot in
Or
.child("comments").observe(.childChanged) { snapshot in
to listen to added childs
I have data in my db and can search for an individual record, that's working fine. But when I try to simply populate a tableview with all of the db records its not receiving/displaying any data.
here is my code:
struct drinkStruct {
let pub: String!
let rating: String!
let price: String!
}
override func viewDidLoad() {
super.viewDidLoad()
loadDrinks()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func homeClicked(_ sender: Any) {
homeClicked()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
let label1 = cell.viewWithTag(1) as! UILabel
label1.text = posts[indexPath.row].pub
let label2 = cell.viewWithTag(2) as! UILabel
label2.text = posts[indexPath.row].rating
let label3 = cell.viewWithTag(3) as! UILabel
label3.text = posts[indexPath.row].price
return cell
}
func loadDrinks(){
let databaseRef = Database.database().reference().child("Drinks")
ref = Database.database().reference()
databaseRef.queryOrderedByKey().observe(.childAdded, with: { (snapshot) in
if let valueDictionary = snapshot.value as? [AnyHashable:String]
{
let pub = valueDictionary["pub"]
let rating = valueDictionary["rating"]
let price = valueDictionary["price"]
self.posts.insert(drinkStruct(pub: pub, rating: rating, price: price), at: 0)
}
})
self.tableview.reloadData()
}
And here is my db structure:
Am I doing something blatantly obviously wrong? Or can anyone see what's causing no data to load?
There are no errors/unused variables etc etc.
Thanks in advance!
I think the following should do the job.
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
override func viewDidLoad() {
super.viewDidLoad()
//getting a reference to the node //
databaseRef = Database.database().reference().child("Drinks")
//observing the data changes
databaseRef.observe(DataEventType.value, with: { (snapshot) in
if snapshot.childrenCount > 0 {
// clearing the list //
self.posts.removeAll()
// iterating through all the values //
for drinks in snapshot.children.allObjects as! [DataSnapshot] {
let drinkObject = drinks.value as! [String: AnyObject]
let drinkPub = drinkObject["pub"]
let drinkRating = drinkObject["rating"]
let drinkPrice = drinkObject["price"]
//creating a drinkStruct object with the model //
let drinkModel = drinkStruct(pub: drinkPub as! String?, rating: drinkRating as! String?, price: drinkPrice as! String?)
//appending it to list
self.posts.append(drinkModel)
}
// reloading data //
self.tableView.reloadData()
}
})
}
var posts = [drinkStruct]()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! YourCustomTableViewCell
let drink: drinkStruct
drink = posts[indexPath.row]
cell.label1.text = drink.pub
cell.label2.text = drink.rating
cell.label3.text = drink.price
return cell
}
}
For the newbie that's here in my footsteps, I solved this by doing a lot of things.
You need to create the tableview & cell layout in the storyboard. Then you need a cell class that dictates/assigns what's happening in each cell(imageviews, labels etc) as well as a model class for whatever you're looking up, whatever the object may be.
This is the code I used for my function in which I populate the info in the cells with the data from Firebase:
func loadDrinks(){
Database.database().reference().child("Drinks").observe(.childAdded) { (snapshot: DataSnapshot) in
if let dict = snapshot.value as? [String: Any] {
let pub = dict["pub"] as! String
let rating = dict["rating"] as! String
let price = dict["price"] as! String
let drink = Drink(pub: pub.capitalized, rating: rating.capitalized, price: price.capitalized)
self.drinks.append(drink)
print(self.drinks)
self.tableview.reloadData()
}
}
}
This was a Newbie 101 question - my bad.
I am trying to use the SDImageView Cocoapod with a table view to retrieve a URL from a database and turning it into a viewable image. When I use the code bellow I don't get images in return, what is wrong with my code? Thanks!
var posts = [postStruct]()
override func viewDidLoad() {
super.viewDidLoad()
let ref = Database.database().reference().child("Posts")
ref.observeSingleEvent(of: .value, with: { snapshot in
print(snapshot.childrenCount)
for rest in snapshot.children.allObjects as! [DataSnapshot] {
guard let value = rest.value as? Dictionary<String,Any> else { continue }
guard let title = value["Title"] as? String else { continue }
guard let downloadURL = value["Download URL"] as? String else { continue }
let post = postStruct(title: title, downloadURL: downloadURL)
self.posts.append(post)
}
self.posts = self.posts.reversed(); self.tableView.reloadData()
})
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
let imageView = cell?.viewWithTag(200) as! UIImageView
imageView.sd_setImage(with: URL(string: "downloadURL"), placeholderImage: UIImage(named: "placeholder.png"))
let label1 = cell?.viewWithTag(1) as! UILabel
label1.text = posts[indexPath.row].title
return cell!
}
You need to change SDWebimage syntax as ->
var posts = [postStruct]()
var downloadURL : String = ""
override func viewDidLoad() {
super.viewDidLoad()
let ref = Database.database().reference().child("Posts")
ref.observeSingleEvent(of: .value, with: { snapshot in
print(snapshot.childrenCount)
for rest in snapshot.children.allObjects as! [DataSnapshot] {
guard let value = rest.value as? Dictionary<String,Any> else { continue }
guard let title = value["Title"] as? String else { continue }
downloadURL = value["Download URL"] as? String ?? ""
let post = postStruct(title: title, downloadURL: downloadURL)
self.posts.append(post)
}
self.posts = self.posts.reversed(); self.tableView.reloadData()
})
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
let imageView = cell?.viewWithTag(200) as! UIImageView
imageView.sd_setImage(with: URL(string: downloadURL), placeholderImage: UIImage(named: "placeholder.png"))
let label1 = cell?.viewWithTag(1) as! UILabel
label1.text = posts[indexPath.row].title
return cell!
}
Where downloadURL is url String.
You first need to pick the postStruct from the array and then the downloadURL. Change your override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell method with this.
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
let imageView = cell?.viewWithTag(200) as! UIImageView
let post = self.posts[indexPath.row];
imageView.sd_setImage(with: URL(string: post.downloadURL), placeholderImage: UIImage(named: "placeholder"))
let label1 = cell?.viewWithTag(1) as! UILabel
label1.text = posts[indexPath.row].title
return cell!
}