Swift Firebase UIRefreshControl

Question

I am trying to reload my tableview so users can get refreshed data related to their location. My current setup has it to where when I do a "pull to refresh" it will start adding duplicate data to the tableview instead of clearing it and replacing it with the new data. I feel like there is 1 line of code that will solve this problem but I don't know what it is, I feel like I've seen it before somewhere...

var refresher: UIRefreshControl!

override func viewDidLoad() {
    super.viewDidLoad()


    searchController.searchResultsUpdater = self
    searchController.dimsBackgroundDuringPresentation = false
    definesPresentationContext = true
    tableView.tableHeaderView = searchController.searchBar

    locationManager.delegate = self
    locationManager.distanceFilter = kCLLocationAccuracyNearestTenMeters
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.startUpdatingLocation()
    locationManager.stopUpdatingLocation()

    getTableViewData()

    refresher = UIRefreshControl()
    refresher.attributedTitle = NSAttributedString(string: "Pull to refresh")
    refresher.addTarget(self, action: #selector(RegisteredLocationsTableView.handleRefresh(refreshControl:)), for: UIControlEvents.valueChanged)
    tableView.addSubview(refresher)
}

func handleRefresh(refreshControl: UIRefreshControl) {
    getTableViewData()

    self.tableView.reloadData()
    refreshControl.endRefreshing()
}

func getTableViewData() {
    databaseRef.child("Businesses").queryOrdered(byChild: "businessName").observe(.childAdded, with: { (snapshot) in

        let key = snapshot.key

        if(key == self.loggedInUser?.uid) {
            print("Same as logged in user, so don't show!")
        } else {
            if let locationValue = snapshot.value as? [String: AnyObject] {
                let lat = Double(locationValue["businessLatitude"] as! String)
                let long = Double(locationValue["businessLongitude"] as! String)
                let businessLocation = CLLocation(latitude: lat!, longitude: long!)

                let latitude = self.locationManager.location?.coordinate.latitude
                let longitude = self.locationManager.location?.coordinate.longitude
                let userLocation = CLLocation(latitude: latitude!, longitude: longitude!)

                let distanceInMeters : Double = userLocation.distance(from: businessLocation)
                let distanceInMiles : Double = ((distanceInMeters.description as String).doubleValue * 0.00062137)
                let distanceLabelText = "\(distanceInMiles.string(2)) miles away"

                var singleChildDictionary = locationValue
                singleChildDictionary["distanceLabelText"] = distanceLabelText as AnyObject
                singleChildDictionary["distanceInMiles"] = distanceInMiles as AnyObject
                self.usersArray.append(singleChildDictionary as NSDictionary)
                self.usersArray = self.usersArray.sorted {
                    !($0?["distanceInMiles"] as! Double > $1?["distanceInMiles"] as! Double)
                }
            }
            //insert the rows
            //self.followUsersTableView.insertRows(at: [IndexPath(row:self.usersArray.count-1,section:0)], with: UITableViewRowAnimation.automatic)
            self.followUsersTableView.reloadData()
        }

    }) { (error) in
        print(error.localizedDescription)
    }

}

Answer 1

Inside the method getTableViewData try to do usersArray.removeAll() .

Also I would suggest not doing these inside handleRefresh method:

self.tableView.reloadData()
refreshControl.endRefreshing()

Why: because you need to do it after you get the data using getTableViewData() method. And actually, you already do reload in the end of the getTableViewData() method. So just call also this there refreshControl.endRefreshing() . But you may ask that this refreshControl is not accessible from this method, that means you need to make it as a global property.

Let me know in comments if you need help.

Answer 2

I don't understand what exact issue you are having. But according to the sample code you have posted, in method getTableViewData you are appending data in userArray . So, whenever you are calling handleRefresh new data is getting added in userArray with old data. First clear the previous data of userArray in handleRefresh then call method getTableViewData .