My data from firebase database is not loading into my tableview - ios

I have a tableview loading data from firebase database. When I open my app the data does not populate. when I create a new post I can see the tableview cells modifying like changed were made but the post doesn't populate. I can't figure it out.
import UIKit
import FirebaseAuth
import FirebaseDatabase
class EventsViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var eventsRef: DatabaseReference?
var eventsDatabaseHandle:DatabaseHandle?
var eventsTitles = [String]()
var eventTimestamps = [String]()
var eventsLocations = [String]()
var eventsImages = [UIImage]()
#IBOutlet weak var addEventsButton: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
adminAuth()
eventsRef = Database.database().reference()
tableView.reloadData()
tableView.transform = CGAffineTransform(rotationAngle: -CGFloat.pi)
tableView.delegate = self
tableView.dataSource = self
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { (snaphot) in
let eventPost = snaphot.value as! [String: Any]
self.eventTimestamps.append(eventPost["eventdate"] as! String)
self.eventsTitles.append(eventPost["eventtitle"] as! String)
self.eventsLocations.append(eventPost["eventlocation"] as! String)
let task = URLSession.shared.dataTask(with: URL(string: eventPost["ImageUrl"] as! String)!) {(data, response, error) in
if let image: UIImage = UIImage(data: data!) {
self.eventsImages.append(image)
}
}
self.tableView.reloadData()
task.resume()
})
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return eventsImages.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events") as! EventsTableViewCell
let image = eventsImages[indexPath.row]
cell.flyerImages.image! = image
cell.eventTitle.text! = eventsTitles[indexPath.row]
cell.eventDate.text! = eventTimestamps[indexPath.row]
cell.eventLocation.text! = eventsLocations[indexPath.row]
cell.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
tableView.reloadData()
return cell
}
func adminAuth() {
if (Auth.auth().currentUser!.displayName != "Neil Leon") {
self.addEventsButton.tintColor = UIColor.clear
self.addEventsButton.isEnabled = false
}
else{
self.addEventsButton.isEnabled = true
}
}
}
image of empty tableview
]

So the code below is not tested as I don't have firebase setup currently.
However, observing childAdded... the documentation says it will pass all of the current records in the database at first and will then just post new additions. So all you need to do is loop through them, setup your tableView data source and reload the table.
Rather than use multiple arrays for values I've created an array of ChurchEvent objects instead.
struct ChurchEvents {
let title: String
let location: String?
let date: Date?
let imageUrlString: String?
init(dict: [String: Any]) {
self.title = dict["title"] as String
self.location = dict["location"] as? String
// etc
}
}
var events = [ChurchEvents]()
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { snapshot in
let list = snapshot.value as? [[String : AnyObject]]
let newEvents = list.map { ChurchEvent(dict: $0) }
events.append(newEvents)
tableView.reloadData()
}
Other improvements you could make:
class EventsTableViewCell: UICollectionViewCell {
func configure(with event: ChurchEvent {
eventDate.text = event.date
eventTitle.text = event.title
eventLocation.text = event.location
// etc
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events") as! EventsTableViewCell
let event = events[indexPath.row]
cell.configure(with: event)
return cell
}

Related

Index out of range error keeps crashing my app

I have a tableview loading data from firebase database. When i open my app the data does not populate. it crashes and throws the error index out of range. I am fairly new to xcode and would appreciate the help. i have been given recommendations on how to fix my code with regards to having multiple arrays but everyone that advices forget i'm new and does realize that i am pulling imageurls into my tableview too and dont know how to adopt their recommendations into my code. if i could get help getting passed this error that would be awesome.
import UIKit
import FirebaseAuth
import FirebaseDatabase
class EventsViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var eventsRef: DatabaseReference?
var eventsDatabaseHandle:DatabaseHandle?
var eventsTitles = [String]()
var eventTimestamps = [String]()
var eventsLocations = [String]()
var eventsImages = [UIImage]()
#IBOutlet weak var addEventsButton: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
adminAuth()
eventsRef = Database.database().reference()
tableView.reloadData()
tableView.transform = CGAffineTransform(rotationAngle: -CGFloat.pi)
tableView.delegate = self
tableView.dataSource = self
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { (snaphot) in
let eventPost = snaphot.value as! [String: Any]
self.eventTimestamps.append(eventPost["eventdate"] as! String)
self.eventsTitles.append(eventPost["eventtitle"] as! String)
self.eventsLocations.append(eventPost["eventlocation"] as! String)
let task = URLSession.shared.dataTask(with: URL(string: eventPost["ImageUrl"] as! String)!) {(data, response, error) in
if let image: UIImage = UIImage(data: data!) {
self.eventsImages.append(image)
}
}
task.resume()
self.tableView.reloadData()
})
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return eventsTitles.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events") as! EventsTableViewCell
// let image = eventsImages[indexPath.row]
cell.flyerImages.image? = eventsImages[indexPath.row] **<- index out of range**
cell.eventTitle.text! = eventsTitles[indexPath.row]
cell.eventDate.text! = eventTimestamps[indexPath.row]
cell.eventLocation.text! = eventsLocations[indexPath.row]
cell.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
return cell
}
func adminAuth() {
if (Auth.auth().currentUser!.displayName != "Neil Leon") {
self.addEventsButton.tintColor = UIColor.clear
self.addEventsButton.isEnabled = false
}
else{
self.addEventsButton.isEnabled = true
}
}
}``````
At the moment reloadData is called the image array is empty and causes the crash
Use a custom struct and reload the table view after the image data has been received
struct Event {
let title, timestamp, location : String
var image : UIImage?
}
var events = [Event]()
...
eventsDatabaseHandle = eventsRef?.child("Church Events").observe(.childAdded, with: { (snaphot) in
let eventPost = snaphot.value as! [String: Any]
let event = Event(title: eventPost["eventtitle"] as! String,
timestamp: eventPost["eventdate"] as! String,
location: eventPost["eventlocation"] as! String,
image: nil)
let task = URLSession.shared.dataTask(with: URL(string: eventPost["ImageUrl"] as! String)!) { data, _, error in
if let error = error {
print(error)
} else {
event.image = UIImage(data: data!)
DispatchQueue.main.async {
self.events.append(event)
self.tableView.reloadData()
}
}
}
task.resume()
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return events.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "events", for: indexPath) as! EventsTableViewCell
let event = events[indexPath.row]
cell.flyerImages.image = event.image
cell.eventTitle.text = event.title
cell.eventDate.text = event.timestamp
cell.eventLocation.text = event.location
cell.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
return cell
}

How to group tableview cells based on field in JSON array

Essentially I have am using JSON data to create an array and form a tableview.
I would like the table cells to be grouped by one of the fields from the JSON array.
This is what the JSON data looks like:
[{"customer":"Customer1","number":"122039120},{"customer":"Customer2","number":"213121423"}]
Each number needs to be grouped by each customer.
How can this be done?
This is how I've implemented the JSON data using the table:
CustomerViewController.swift
import UIKit
class CustomerViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, FeedCustomerProtocol {
var feedItems: NSArray = NSArray()
var selectedStock : StockCustomer = StockCustomer()
let tableView = UITableView()
#IBOutlet weak var customerItemsTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
//set delegates and initialize FeedModel
self.tableView.allowsMultipleSelection = true
self.tableView.allowsMultipleSelectionDuringEditing = true
self.customerItemsTableView.delegate = self
self.customerItemsTableView.dataSource = self
let feedCustomer = FeedCustomer()
feedCustomer.delegate = self
feedCustomer.downloadItems()
}
}
func itemsDownloaded(items: NSArray) {
feedItems = items
self.customerItemsTableView.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of feed items
print("item feed loaded")
return feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Retrieve cell
let cell = tableView.dequeueReusableCell(withIdentifier: "customerGoods", for: indexPath) as? CheckableTableViewCell
let cellIdentifier: String = "customerGoods"
let myCell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
// Get the stock to be shown
let item: StockCustomer = feedItems[indexPath.row] as! StockCustomer
// Configure our cell title made up of name and price
let titleStr = [item.number].compactMap { $0 }.joined(separator: " - ")
return myCell
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
tableView.cellForRow(at: indexPath)?.accessoryType = .none
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
let cellIdentifier: String = "customerGoods"
let myCell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
myCell.textLabel?.textAlignment = .left
}
}
FeedCustomer.swift:
import Foundation
protocol FeedCustomerProtocol: class {
func itemsDownloaded(items: NSArray)
}
class FeedCustomer: NSObject, URLSessionDataDelegate {
weak var delegate: FeedCustomerProtocol!
let urlPath = "https://www.example.com/example/test.php"
func downloadItems() {
let url: URL = URL(string: urlPath)!
let defaultSession = Foundation.URLSession(configuration: URLSessionConfiguration.default)
let task = defaultSession.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Error")
}else {
print("stocks downloaded")
self.parseJSON(data!)
}
}
task.resume()
}
func parseJSON(_ data:Data) {
var jsonResult = NSArray()
do{
jsonResult = try JSONSerialization.jsonObject(with: data, options:JSONSerialization.ReadingOptions.allowFragments) as! NSArray
} catch let error as NSError {
print(error)
}
var jsonElement = NSDictionary()
let stocks = NSMutableArray()
for i in 0 ..< jsonResult.count
{
jsonElement = jsonResult[i] as! NSDictionary
let stock = StockCustomer()
//the following insures none of the JsonElement values are nil through optional binding
if let number = jsonElement[“number”] as? String,
let customer = jsonElement["customer"] as? String,
{
stock.customer = customer
stock.number = number
}
stocks.add(stock)
}
DispatchQueue.main.async(execute: { () -> Void in
self.delegate.itemsDownloaded(items: stocks)
})
}
}
StockCustomer.swift:
import UIKit
class StockCustomer: NSObject {
//properties of a stock
var customer: String?
var number: String?
//empty constructor
override init()
{
}
//construct with #name and #price parameters
init(customer: String) {
self.customer = customer
}
override var description: String {
return "Number: \(String(describing: number)), customer: \(String(describing: customer))"
}
}
You can achieve this by making an array of array. So something like this
[[{"customer": "customer1", "number": "123"}, {"customer": "customer1", "number": "456"}], [{"customer": "customer2", "number": "678"}, {"customer": "customer2", "number": "890"}]]
This is not the only data structure you can use to group. Another possibility is:
{"customer1": [{"customer": "customer1", "number": "123"}, {"customer": "customer1", "number": "456"}], "customer2": [{"customer": "customer2", "number": "678"}, {"customer": "customer2", "number": "890"}]}
Then you can use UITableView sections to group by customers. Section count would be the number of inside arrays and each section would contain as many rows as there are numbers in that inside array.
You can group a sequence based on a particular key using one of the Dictionary initializer,
init(grouping:by:)
The above method init will group the given sequence based on the key you'll provide in its closure.
Also, for parsing such kind of JSON, you can easily use Codable instead of manually doing all the work.
So, for that first make StockCustomer conform to Codable protocol.
class StockCustomer: Codable {
var customer: String?
var number: String?
}
Next you can parse the array like:
func parseJSON(data: Data) {
do {
let items = try JSONDecoder().decode([StockCustomer].self, from: data)
//Grouping the data based on customer
let groupedDict = Dictionary(grouping: items) { $0.customer } //groupedDict is of type - [String? : [StockCustomer]]
self.feedItems = Array(groupedDict.values)
} catch {
print(error.localizedDescription)
}
}
Read about init(grouping:by:) in detail here: https://developer.apple.com/documentation/swift/dictionary/3127163-init
Make the feedItems object in CustomerViewController of type [[StockCustomer]]
Now, you can implement UITableViewDataSource methods as:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "customerGoods", for: indexPath) as! CheckableTableViewCell
let items = self.feedItems[indexPath.row]
cell.textLabel?.text = items.compactMap({$0.number}).joined(separator: " - ")
//Configure the cell as per your requirement
return cell
}
Try implementing the approach with all the bits and pieces and let me know in case you face any issues.

iOS / Swift - Appending a filter to retrieving data from Firebase

What I got so far is a tableView and custom Cells about hookah tobacco. Those include an image, name, brand and ID. Now what I try to reach is basically a tableview that contains only the cells with attributes based on a "filter". For example the tableView that appears at the beginning has only the following two settings to make it simple: PriceRange and BrandName. At the first time loading the tableView those are PriceRange: 0 - 100 and Brands: all brands. Then imagine a user restricting those like 0 - 15 Euros and only brand called "7 Days". How exactly would I do that with reloading the tableView?
import UIKit
import Firebase
class ShopViewController: UIViewController, UISearchBarDelegate {
#IBOutlet weak var button_filter: UIBarButtonItem!
#IBOutlet weak var searchBar_shop: UISearchBar!
#IBOutlet weak var view_navigator: UIView!
#IBOutlet weak var tableView_shop: UITableView!
var ShopCells: [ShopCell] = []
var databaseRef: DatabaseReference!
var storageRef: StorageReference!
override func viewDidLoad() {
super.viewDidLoad()
self.databaseRef = Database.database().reference()
self.storageRef = Storage.storage().reference()
createArray() { shopCells in
for item in shopCells {
self.ShopCells.append(item)
}
DispatchQueue.main.async {
self.tableView_shop.reloadData()
}
}
self.navigationItem.title = "Shop"
self.tableView_shop.delegate = self
self.tableView_shop.dataSource = self
self.searchBar_shop.delegate = self
self.searchBar_shop.barTintColor = UIColor(hexString: "#1ABC9C")
self.view_navigator.backgroundColor = UIColor(hexString: "#1ABC9C")
self.tableView_shop.separatorColor = UIColor.clear
self.searchBar_shop.isTranslucent = false
self.searchBar_shop.backgroundImage = UIImage()
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(ShopViewController.viewTapped(gestureRecognizer:)))
view.addGestureRecognizer(tapGesture)
}
#objc func viewTapped(gestureRecognizer: UITapGestureRecognizer) {
view.endEditing(true)
}
func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
self.searchBar_shop.resignFirstResponder()
}
func createArray(completion: #escaping ([ShopCell]) -> () ) {
var tempShopCells: [ShopCell] = []
let rootRef = Database.database().reference()
let query = rootRef.child("tobaccos").queryOrdered(byChild: "name")
query.observeSingleEvent(of: .value) { (snapshot) in
let dispatchGroup = DispatchGroup()
for child in snapshot.children.allObjects as! [DataSnapshot] {
let value = child.value as? [String: Any];
let name = value?["name"] as? String ?? "";
let brand = value?["brand"] as? String ?? "";
let iD = value?["iD"] as? String ?? "";
dispatchGroup.enter()
let imageReference = Storage.storage().reference().child("tobaccoPictures").child("\(iD).jpg")
imageReference.getData(maxSize: (1 * 1024 * 1024)) { (data, error) in
if let _error = error{
print(_error)
} else {
if let _data = data {
let image: UIImage! = UIImage(data: _data)
tempShopCells.append(ShopCell(productName: name, brandName: brand, productImage: image, iD: iD))
}
}
dispatchGroup.leave()
}
}
dispatchGroup.notify(queue: .main) {
completion(tempShopCells)
}
}
}
}
extension ShopViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.ShopCells.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let shopCell = ShopCells[indexPath.row]
let cell = tableView_shop.dequeueReusableCell(withIdentifier: "ShopCell") as! ShopTableViewCell
cell.setShopCell(shopCell: shopCell)
return cell
}
}

How to pull users from database and list them in a table view using firebase?

I'm using firebase to make an iOS app. I want to retrieve all the users on my database and display their name and profile picture in a table view. Here is my code for my TableViewCell:
import UIKit
import FirebaseDatabase
import FirebaseAuth
import SDWebImage
class HomeTableViewCell: UITableViewCell {
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var profileImageView: UIImageView!
#IBOutlet weak var likeImageView: UIImageView!
#IBOutlet weak var messageImageView: UIImageView!
#IBOutlet weak var likeCountButton: UIButton!
var homeVC: HomeViewController?
var postReference: DatabaseReference!
var post: UserFile?{
didSet {
updateView()
}
}
var user: UserFile? {
didSet {
updateUserInfo()
}
}
override func awakeFromNib() {
super.awakeFromNib()
nameLabel.text = ""
let berryTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleLikeTap))
likeImageView.addGestureRecognizer(berryTapGesture)
likeImageView.isUserInteractionEnabled = true
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
func updateView() {
if let photoURL = post?.picURL {
profileImageView.sd_setImage(with: URL(string: photoURL))
}
API.Post.REF_POSTS.child(post!.id!).observeSingleEvent(of: .value, with: { postSnapshot in
if let postDictionary = postSnapshot.value as? [String:Any] {
let post = UserFile.transformPost(postDictionary: postDictionary, key: postSnapshot.key)
self.updateLike(post: post)
}
})
API.Post.REF_POSTS.child(post!.id!).observe(.childChanged, with: { snapshot in
if let value = snapshot.value as? Int {
self.likeCountButton.setTitle("\(value) berries", for: .normal)
}
})
}
func updateLike(post: UserFile) {
let imageName = post.berries == nil || !post.isBerried! ? "berry" : "berrySelected"
likeImageView.image = UIImage(named: imageName)
// display a message for berries
guard let count = post.berryCount else {
return
}
if count != 0 {
likeCountButton.setTitle("\(count) berries", for: .normal)
} else if post.berryCount == 0 {
likeCountButton.setTitle("Be the first to Like this", for: .normal)
}
}
func incrementberries(forReference ref: DatabaseReference) {
ref.runTransactionBlock({ (currentData: MutableData) -> TransactionResult in
if var post = currentData.value as? [String : AnyObject], let uid = Auth.auth().currentUser?.uid {
var berries: Dictionary<String, Bool>
berries = post["berries"] as? [String : Bool] ?? [:]
var likeCount = post["berryCount"] as? Int ?? 0
if let _ = berries[uid] {
// Unlike the post and remove self from stars
likeCount -= 1
berries.removeValue(forKey: uid)
} else {
// Like the post and add self to stars
likeCount += 1
berries[uid] = true
}
post["berryCount"] = likeCount as AnyObject?
post["berries"] = berries as AnyObject?
currentData.value = post
return TransactionResult.success(withValue: currentData)
}
return TransactionResult.success(withValue: currentData)
}) { (error, committed, snapshot) in
if let error = error {
print(error.localizedDescription)
}
if let postDictionary = snapshot?.value as? [String:Any] {
let post = UserFile.transformPost(postDictionary: postDictionary, key: snapshot!.key)
self.updateLike(post: post)
}
}
}
func handleLikeTap() {
postReference = API.Post.REF_POSTS.child(post!.id!)
incrementberries(forReference: postReference)
}
override func prepareForReuse() {
super.prepareForReuse()
profileImageView.image = UIImage(named: "industribune-default-no-profile-pic")
}
func updateUserInfo() {
nameLabel.text = user?.username
if let photoURL = user?.profileImageURL {
profileImageView.sd_setImage(with: URL(string: photoURL), placeholderImage: UIImage(named: "industribune-default-no-profile-pic"))
}
}
}
I am displaying this cell on my HomeViewController:
import UIKit
import FirebaseAuth
import FirebaseDatabase
import FirebaseStorage
import Firebase
class HomeViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var activityIndicatorView: UIActivityIndicatorView!
var posts = [UserFile]()
var users = [UserFile]()
override func viewDidLoad() {
super.viewDidLoad()
// for performance set an estimated row height
tableView.estimatedRowHeight = 1
// but also request to dynamically adjust to content using AutoLayout
tableView.rowHeight = UITableViewAutomaticDimension
//tableView.delegate = self
tableView.dataSource = self
loadPosts()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func loadPosts() {
activityIndicatorView.startAnimating()
API.User.observePosts { (newPost) in
guard let userID = newPost.uid else { return }
self.fetchUser(uid: userID, completed: {
// append the new Post and Reload after the user
// has been cached
self.posts.append(newPost)
self.activityIndicatorView.stopAnimating()
self.tableView.reloadData()
})
}
}
func fetchUser(uid: String, completed: #escaping () -> Void) {
API.User.observeUser(withID: uid) { user in
self.users.append(user)
completed()
}
}
}
extension HomeViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "HomeTableViewCell", for: indexPath) as! HomeTableViewCell
cell.post = posts[indexPath.row]
cell.user = users[indexPath.row]
cell.homeVC = self
return cell
}
}
I have a lot of craziness going on in my project so let me know if you have any questions and what I'm doing wrong. If it's too complicated to understand I'm ready to erase everything and start over too.
And I do honestly think that I followed all the guidelines to ask a question so don't like shut this question down or something.
That's a lot of code. Try this super reduced example. For this, the users node only stores the name as a child node but it could also have an image, email, address, etc.
Example users node
users
uid_0:
name: "Bert"
uid_1:
name: "Ernie"
and some code
var usersArray = [ [String: Any] ]() //an array of dictionaries.
class ViewController: UIViewController {
//set up firebase references here
override func viewDidLoad() {
super.viewDidLoad()
let usersRef = self.ref.child("users")
usersRef.observeSingleEvent(of: .value, with: { snapshot in
for child in snapshot.children {
let snap = child as! DataSnapshot
let userDict = snap.value as! [String: Any]
self.usersArray.append(userDict)
}
self.tableView.reloadData()
})
and the tableView delegate methods
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.usersArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "HomeTableViewCell", for: indexPath) as! HomeTableViewCell
let userDict = self.usersArray[indexPath.row]
cell.text = userDict["name"] as! String
//cell.imge = userDict["image"] etc etc
return cell
}
Now... that all being said. This is the perfect use for an array of UserClass objects instead of the dictionaries.
Here's a starting point....
class UserClass {
var name = ""
var image = ""
func init(snap: DataSnapshot) {
//populate the vars from the snapshot
}
}
var userClassArray = [UserClass]()
Don't copy and paste this as there are probably typos but it should point you in the right direction.

How to display data in Firebase that is held under a autoID child?

I am creating an inventory app in order to keep track of items held in a laboratory. In the laboratory there are different stations which contain different items in them, which as you can see is structured properly in my Firebase database.
Firebase Database
Iphone Simulator
My problem comes when I try to delete a particular item out of the tableCell. I am able to remove it from the UI but in firebase the data still remains. I have done coutless reserch but am not able to find anything relating to this particular problem.
Data Services Class
let DB_BASE = FIRDatabase.database().reference().child("laboratory") //contains the root of our database
let STORAGE_BASE = FIRStorage.storage().reference()
class DataService {
static let ds = DataService()
//DB References
private var _REF_BASE = DB_BASE
private var _REF_STATION = DB_BASE.child("stations")
private var _REF_USERS = DB_BASE.child("users")
//Storage Reference
private var _REF_ITEM_IMAGE = STORAGE_BASE.child("item-pics")
var REF_BASE: FIRDatabaseReference {
return _REF_BASE
}
var REF_STATION: FIRDatabaseReference {
return _REF_STATION
}
var REF_USERS: FIRDatabaseReference {
return _REF_USERS
}
var REF_ITEM_IMAGES: FIRStorageReference {
return _REF_ITEM_IMAGE
}
//creating a new user into the firebase database
func createFirebaseDBUser(_ uid: String, userData: Dictionary<String, String>) {
REF_USERS.child(uid).updateChildValues(userData)
}
}
Inventory View Controller
import UIKit
import Firebase
class InventoryViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
var items = [Item]()
private var _station: Station!
private var _item: Item!
var sortIndex = 3
var imagePicker: UIImagePickerController!
static var imageCache: NSCache<NSString, UIImage> = NSCache()
var imageSelected = false
#IBOutlet weak var itemImageToAdd: UIImageView!
#IBOutlet weak var objectTextInput: UITextField!
#IBOutlet weak var brandTextInput: UITextField!
#IBOutlet weak var unitTextInput: UITextField!
#IBOutlet weak var amountTextInput: UITextField!
#IBOutlet weak var tableView: UITableView!
#IBOutlet var addItemView: UIView!
#IBOutlet weak var currentStationLabel: UILabel!
var station: Station {
get {
return _station
} set {
_station = newValue
}
}
override func viewDidLoad() {
super.viewDidLoad()
var currentStationName = station.title
currentStationLabel.text = currentStationName
self.items = []
let currentStation = station.title
let stationRef = DataService.ds.REF_STATION.child(currentStation!)
let inventoryRef = stationRef.child("inventory")
tableView.delegate = self
tableView.dataSource = self
imagePicker = UIImagePickerController()
imagePicker.allowsEditing = true
imagePicker.delegate = self
inventoryRef.observe(.value, with: { (snapshot) in
print(snapshot.value!)
self.items = []
if let snapshot = snapshot.children.allObjects as? [FIRDataSnapshot] {
for snap in snapshot {
print("SNAP: \(snap)")
if let itemDict = snap.value as? Dictionary<String, AnyObject> {
let key = snap.key
let item = Item(itemKey: key,
itemData: itemDict)
self.items.append(item)
}
}
}
self.tableView.reloadData()
})
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let item = items[indexPath.row]
if let cell = tableView.dequeueReusableCell(withIdentifier: "inventoryTableCell", for: indexPath) as? ItemCell {
if let img = InventoryViewController.imageCache.object(forKey: NSString(string: item.imageURL!)) {
cell.updateItemUI(item: item, img: img)
} else {
cell.updateItemUI(item: item)
}
return cell
} else {
return ItemCell()
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func postToFirebase(itemImageURL: String) {
let post: Dictionary<String, AnyObject> = [
"objectLabel": objectTextInput.text! as AnyObject,
"brandLabel": brandTextInput.text! as AnyObject,
"unitLabel": unitTextInput.text! as AnyObject,
"amountLabel": amountTextInput.text! as AnyObject,
//post elsewhere as an image for future reference
"itemImageURL": itemImageURL as AnyObject,
]
let stationText = _station.title
let stationRef = DataService.ds.REF_STATION.child(stationText!)
let inventoryRef = stationRef.child("inventory")
let firebasePost = inventoryRef.childByAutoId()
firebasePost.setValue(post)
objectTextInput.text = ""
brandTextInput.text = ""
unitTextInput.text = ""
amountTextInput.text = ""
imageSelected = false
tableView.reloadData()
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
if let image = info[UIImagePickerControllerEditedImage] as? UIImage {
itemImageToAdd.image = image
imageSelected = true
} else {
print("Please select a valid image")
}
imagePicker.dismiss(animated: true, completion: nil)
}
#IBAction func backToStations(_ sender: Any) {
performSegue(withIdentifier: "backToStations", sender: nil)
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(tableView: (UITableView!), commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: (NSIndexPath!)) {
}
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let currentStation = station.title
let stationRef = DataService.ds.REF_STATION.child(currentStation!)
let inventoryRef = stationRef.child("inventory")
var deleteAction = UITableViewRowAction(style: .default, title: "Delete") {action in
//Insert code to delete values from Firebase
self.items.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath as IndexPath], with: .fade)
}
var editAction = UITableViewRowAction(style: .normal, title: "Edit") { action in
}
return [deleteAction, editAction]
}
}
My thought process is upon delete to call self_items.key reffering to the current key of the particular tableCell row. From there I would use the current key whick would be the autoID and remove the value that way. Unfortunatly though that crashes the program with a fatal nil error.
The best way I've found to solve this problem is in your delete action, delete the object from Firebase. Do not alter the tableview from here.
Then in your data listener, check when the data comes back as deleted(or NULL), then remove it from the tableview datasource array and update the tableview.

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