How to get the key of a value in Firebase? - firebase

Question

I'm using Swift 3
I have this social network like twitter and im trying to retrive the user's following list but i'm having some troubles, my idea is to get them so i can use them to then do a for loop and retrive the Posts or Tweets, so something like this
self.databaseRef.child("following").child((self.loggedInUser?.uid)!).observeSingleEvent(of: .value) { (snapshot:FIRDataSnapshot) in
for child in snapshot.children {
self.databaseRef.child("Jalas").child((child as AnyObject).key!).observe(.childAdded, with: { (snapshot:FIRDataSnapshot) in
if (snapshot.value as? NSDictionary != nil)
{
self.Jalas.append(snapshot.value as! NSDictionary)
}
}){(error) in
print(error.localizedDescription)
}
}
self.homeTableView.beginUpdates()
self.homeTableView.insertRows(at: [IndexPath(row:0,section:0)], with: UITableViewRowAnimation.automatic)
self.homeTableView.endUpdates()
self.aivLoading.stopAnimating()
}
and in number of rows in section i'm returning self.Jalas.count but this does nothing. and it throws me an error.
"attempt to insert row 0 into section 0, but there are only 0 rows in section 0 after the update"
this is my database.
Jalas = Posts
{
"Jalas" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : {
"-KbHUnL-RveUQa3MPSWp" : {
"latitud" : "21.111401000574",
"longitud" : "-89.6112191677094",
"text" : "Fiesta en la Anahuac!!! ",
"timestamp" : "1485295269.30773",
"ubicacionN" : "Universidad Anáhuac Mayab"
},
"-KbI1azr6uFel-5uTZOD" : {
"latitud" : "Optional(21.018988764483463)",
"longitud" : "Optional(-89.614319546492695)",
"text" : "Hola chicos",
"timestamp" : "1485304393.77929",
"ubicacionN" : "Calle 53-A 341"
},
"-KbNQWxjQhc0Ce_ZQbq9" : {
"latitud" : "Optional(21.019219877217914)",
"longitud" : "Optional(-89.614173537203683)",
"text" : "Hola",
"timestamp" : "1485394812.83039",
"ubicacionN" : "Calle 53 341"
}
},
"mt0fzirhMhazIcy90MRWuRpTfmE2" : {
"-KbQOWfUnzY1JiS61J6-" : {
"latitud" : "Optional(21.111502615883129)",
"longitud" : "Optional(-89.611767497121221)",
"text" : "Hola chicos!",
"timestamp" : "1485444619.10931",
"ubicacionN" : "Carretera Mérida-Progreso 96"
}
}
},
"follower" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : {
"mt0fzirhMhazIcy90MRWuRpTfmE2" : true
},
"mt0fzirhMhazIcy90MRWuRpTfmE2" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : true
}
},
"following" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : {
"mt0fzirhMhazIcy90MRWuRpTfmE2" : true
},
"mt0fzirhMhazIcy90MRWuRpTfmE2" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : true
}
},
"handles" : {
"jcadmin" : "mt0fzirhMhazIcy90MRWuRpTfmE2",
"jcbest" : "dEXaVLDOSPfJa3zTyUNqAEtVuMR2"
},
"user_profiles" : {
"dEXaVLDOSPfJa3zTyUNqAEtVuMR2" : {
"about" : "Hola Mundo",
"handle" : "jcbest",
"name" : "Juan Carlos Estevez Rodriguez",
"profile_pic" : "https://firebasestorage.googleapis.com/v0/b/jalo-267da.appspot.com/o/user_profiles%2FOptional(%22dEXaVLDOSPfJa3zTyUNqAEtVuMR2%22)%2Fprofile_pic?alt=media&token=bfc3c516-7849-472c-b7cd-9668965a5dbe"
},
"mt0fzirhMhazIcy90MRWuRpTfmE2" : {
"about" : "Hola chicos",
"handle" : "jcadmin",
"name" : "Juan Carlos",
"profile_pic" : "https://firebasestorage.googleapis.com/v0/b/jalo-267da.appspot.com/o/user_profiles%2FOptional(%22mt0fzirhMhazIcy90MRWuRpTfmE2%22)%2Fprofile_pic?alt=media&token=b741b6c1-0bc5-446d-a1e5-159b21e770d2"
}
}
}
This is my entire code.
//
// HomeViewController.swift
// Twitter Clone
//
// Created by Juan Carlos Estevez on 15/12/16.
// Copyright © 2016 JC&C. All rights reserved.
//
import UIKit
import FirebaseDatabase
import FirebaseAuth
import SDWebImage
import ReadMoreTextView
class HomeViewController: UIViewController,UITableViewDelegate,UITableViewDataSource,UIScrollViewDelegate {
var databaseRef = FIRDatabase.database().reference()
var loggedInUser:AnyObject?
var loggedInUserData:NSDictionary?
var listFollowing = [NSDictionary?]()
var listFollowers = [NSDictionary?]()//store all the followers
#IBOutlet weak var aivLoading: UIActivityIndicatorView!
#IBOutlet weak var homeTableView: UITableView!
var defaultImageViewHeightConstraint:CGFloat = 77.0
var Jalas = [NSDictionary]()
override func viewDidLoad() {
super.viewDidLoad()
self.homeTableView.separatorStyle = .none
//self.homeTableView.backgroundView?.backgroundColor = UIColor.init(red: 247, green: 247, blue: 247, alpha: 1)
UITabBar.appearance().tintColor = UIColor.orange
navigationController?.navigationBar.barTintColor = UIColor.orange
Evento.sharedInstance.titulo = ""
Evento.sharedInstance.UbicacionN = nil
self.loggedInUser = FIRAuth.auth()?.currentUser
self.databaseRef.child("following").child((self.loggedInUser?.uid)!).observeSingleEvent(of: .value) { (snapshot:FIRDataSnapshot) in
for child in snapshot.children {
self.databaseRef.child("Jalas").child((child as AnyObject).key!).observeSingleEvent(of: .value) { (snapshot:FIRDataSnapshot) in
//if (snapshot.value as? NSDictionary != nil)
//{
self.Jalas.append(snapshot.value as! NSDictionary)
//}
}
}
//self.homeTableView.beginUpdates()
self.homeTableView.insertRows(at: [IndexPath(row:0,section:0)], with: UITableViewRowAnimation.automatic)
//self.homeTableView.endUpdates()
self.aivLoading.stopAnimating()
}
/*
//get the logged in users details
self.databaseRef.child("user_profiles").child(self.loggedInUser!.uid).observeSingleEvent(of: .value) { (snapshot:FIRDataSnapshot) in
//store the logged in users details into the variable
self.logdInUserData = snapshot.value as? NSDictionary
// print(self.loggedInUserData)
//get all the Jalas that are made by the user
self.databaseRef.child("Jalas").child(self.loggedInUser!.uid).observe(.childAdded, with: { (snapshot:FIRDataSnapshot) in
//self.Jalas.append(snapshot.value as! NSDictionary)
self.homeTableView.insertRows(at: [IndexPath(row:0,section:0)], with: UITableViewRowAnimation.automatic)
self.aivLoading.stopAnimating()
}){(error) in
print(error.localizedDescription)
}
}
*/
//when the user has no posts, stop animating the aiv after 5 seconds
Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(stopAnimating), userInfo: nil, repeats: false)
self.homeTableView.rowHeight = UITableViewAutomaticDimension
self.homeTableView.estimatedRowHeight = 140
/*
self.databaseRef.child("following").child(self.loggedInUser!.uid).observe(.childAdded, with: { (snapshot) in
let snapshot = snapshot.value as? NSDictionary
self.listFollowing.append(snapshot)
print(self.listFollowing)
}) { (error) in
print(error.localizedDescription)
}
self.databaseRef.child("followers").child(self.loggedInUser!.uid).observe(.childAdded, with: { (snapshot) in
let snapshot = snapshot.value as? NSDictionary
self.listFollowers.append(snapshot)
print(self.listFollowers)
}) { (error) in
print(error.localizedDescription)
}
*/
}
#IBAction func NewJalo(_ sender: Any) {
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let welcomeViewController: UIViewController = mainStoryboard.instantiateViewController(withIdentifier: "new")
self.present(welcomeViewController, animated: true, completion: nil)
}
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
UITabBar.appearance().tintColor = UIColor.orange
return true
}
open func stopAnimating()
{
self.aivLoading.stopAnimating()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.Jalas.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
tableView.separatorStyle = .none
var ubicacion = ""
let cell: HomeViewTableViewCell = tableView.dequeueReusableCell(withIdentifier: "HomeViewTableViewCell", for: indexPath) as! HomeViewTableViewCell
cell.contentView.backgroundColor = UIColor.clear
let JaloPost = Jalas[(self.Jalas.count-1) - (indexPath.row)]["text"] as! String
var HG = 105
let CHAR = JaloPost.characters.count
if (CHAR > 30)
{
let CH = ((CHAR/30) * 15)
HG += CH
}
if(Jalas[(self.Jalas.count-1) - (indexPath.row)]["picture"] != nil)
{
HG += 77
}
let whiteRoundedView : UIView = UIView(frame: CGRect(x: 10, y: 8, width: Int(self.view.frame.size.width - 20), height: HG))
whiteRoundedView.layer.backgroundColor = CGColor(colorSpace: CGColorSpaceCreateDeviceRGB(), components: [1.0, 1.0, 1.0, 0.9])
whiteRoundedView.layer.masksToBounds = false
whiteRoundedView.layer.cornerRadius = 2.0
whiteRoundedView.layer.shadowOffset = CGSize(width: -1, height: 1)
whiteRoundedView.layer.shadowOpacity = 0.2
cell.contentView.addSubview(whiteRoundedView)
cell.contentView.sendSubview(toBack: whiteRoundedView)
let imageTap = UITapGestureRecognizer(target: self, action: #selector(self.didTapMediaInTweet(_:)))
cell.tweetImage.addGestureRecognizer(imageTap)
if(Jalas[(self.Jalas.count-1) - (indexPath.row)]["ubicacionN"] != nil)
{
ubicacion = (Jalas[(self.Jalas.count-1) - (indexPath.row)]["ubicacionN"] as? String)!
}
if(Jalas[(self.Jalas.count-1) - (indexPath.row)]["picture"] != nil)
{
cell.tweetImage.isHidden = false
cell.imageViewHeightConstraint.constant = defaultImageViewHeightConstraint
let picture = Jalas[(self.Jalas.count-1) - (indexPath.row)]["picture"] as! String
let url = URL(string:picture)
cell.tweetImage.layer.cornerRadius = 10
cell.tweetImage.layer.borderWidth = 3
cell.tweetImage.layer.borderColor = UIColor.clear.cgColor
cell.tweetImage!.sd_setImage(with: url, placeholderImage: UIImage(named:"twitter")!)
}
else
{
cell.tweetImage.isHidden = true
cell.imageViewHeightConstraint.constant = 0
}
if (self.loggedInUserData!["profile_pic"] == nil)
{
cell.configure(nil,name:self.loggedInUserData!["name"] as! String,handle:self.loggedInUserData!["handle"] as! String,tweet:JaloPost, ubi: ubicacion)
}else
{
cell.configure(self.loggedInUserData!["profile_pic"]! as? String,name:self.loggedInUserData!["name"] as! String,handle:self.loggedInUserData!["handle"] as! String,tweet:JaloPost, ubi: ubicacion)
}
return cell
}
func didTapMediaInTweet(_ sender:UITapGestureRecognizer)
{
let imageView = sender.view as! UIImageView
let newImageView = UIImageView(image: imageView.image)
newImageView.frame = self.view.frame
newImageView.backgroundColor = UIColor.black
newImageView.contentMode = .scaleAspectFit
newImageView.isUserInteractionEnabled = true
let tap = UITapGestureRecognizer(target:self,action:#selector(self.dismissFullScreenImage))
newImageView.addGestureRecognizer(tap)
self.view.addSubview(newImageView)
}
func dismissFullScreenImage(_ sender:UITapGestureRecognizer)
{
sender.view?.removeFromSuperview()
}
/*
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(segue.identifier == "findUserSegue")
{
var showFollowingTableViewController = segue.destination as! FollowUsersTableViewController
showFollowingTableViewController.loggedInUser = self.loggedInUser as? FIRUser
// showFollowingTableViewController.followData = self.followData
}
else if(segue.identifier == "showFollowersTableViewController")
{
var showFollowersTableViewController = segue.destination as! ShowFollowersTableViewController
showFollowersTableViewController.user = self.loggedInUser as? FIRUser
}
}
*/
}
And this is my Table View Cell code.
//
// HomeViewTableViewCell.swift
// Jalo
//
// Created by Juan Carlos Estevez Rodriguez on 24/08/16.
// Copyright © 2016 JC&C. All rights reserved.
//
import UIKit
open class HomeViewTableViewCell: UITableViewCell {
#IBOutlet weak var profilePic: UIImageView!
#IBOutlet weak var name: UILabel!
#IBOutlet weak var handle: UILabel!
#IBOutlet weak var tweet: UITextView!
#IBOutlet weak var tweetImage: UIImageView!
#IBOutlet weak var ubic: UILabel!
#IBOutlet weak var imageViewHeightConstraint: NSLayoutConstraint!
override open func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
open func configure(_ profilePic:String?,name:String,handle:String,tweet:String, ubi:String)
{
self.tweet.text = tweet
self.handle.text = "#"+handle
self.name.text = name
self.ubic.text = ubi
if((profilePic) != nil)
{
let imageData = try? Data(contentsOf: URL(string:profilePic!)!)
self.profilePic.image = UIImage(data:imageData!)
}
else
{
self.profilePic.image = UIImage(named:"twitter")
}
}
}

Answer 1

This
self.homeTableView.beginUpdates()
self.homeTableView.insertRows(at: [IndexPath(row:0,section:0)], with: UITableViewRowAnimation.automatic)
self.homeTableView.endUpdates()
Segment is what's most likely causing your problem. Won't be sure until you edit your question and add the exact error.
When you use .insertRows() in a UITableView, you need to make sure that the count in numberOfRows inSection method also changes accordingly. What you have here is just a mismatch between the number of rows returned by the delegate method and the actual number of rows. Make sure that when you use .insertRows() you return the new expected number of rows in the delegate method!