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iOS

Posted by Youseef Al Taher
Youseef Al Taher
Courses Plus Student 842 Points

Retrieving Data from Parse and displaying in TableView

Hey,

I am having trouble displaying the data that I retrieve from parse in the table view. If I use NSlog() or println(), I see the data retrieved in the console, so I know for a fact that I am receiving the data. I append the data retrieved to an array, and then I try to display this data on the tableview but it keeps coming up empty. If I hard code the data into the array, it gets displayed perfectly. (note: When i print the array in the console, I get the correct data in the array)

I have a feeling that tableview loads before the data is added to the array, hence the data is indeed retrieved, but not displayed. Can anyone help?

The code I have is written below: 

   import Foundation

   import UIKit

   class NameTableView: UITableViewController  {


    @IBOutlet var NameTableView: UITableView!

    //Array of Wroker Names    
    var workerNames: [String] = []


    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {


        return self.workerNames.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {



        var cell = self.NameTableView.dequeueReusableCellWithIdentifier("TransportCell") as UITableViewCell

        cell.textLabel.text = self.workerNames[indexPath.row]

        return cell
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        Parse.setApplicationId("-", clientKey: "-")


        var query = PFQuery(className:"Carpenter")
        query.whereKey("District", equalTo:"Hiliopoless")
        query.findObjectsInBackgroundWithBlock {
            (objects: [AnyObject]!, error: NSError!) -> Void in
            if error == nil {


                // Looping through the objects to get the names of the workers in each object
                for object in objects {

                    //Stringifying the name of the woker
                    var name_of_worker = object["Name"] as String
                    //Adding it to the array of Worker Names
                    self.workerNames.append(name_of_worker)
                    println(self.workerNames)

                }
            } else {
                // Log details of the failure
                NSLog("Error: %@ %@", error, error.userInfo!)
            }
        }      
}
}

1 Answer

Stone Preston
Stone Preston
42,016 Points

you need to reload the data in the tableView to "refresh" it after you get the data from the backend. this will force the delegate and dataSource methods to be called again, updating the tableView cells

// Looping through the objects to get the names of the workers in each object
            for object in objects {

                //Stringifying the name of the woker
                var name_of_worker = object["Name"] as String
                //Adding it to the array of Worker Names
                self.workerNames.append(name_of_worker)
                println(self.workerNames)

                //reload the data
                self.tableView.reloadData()

            }
Youseef Al Taher
Youseef Al Taher
Courses Plus Student 842 Points

It worked Perfectly, Thank you! there is a 2 second lag but whatever.

Stone Preston
Stone Preston
42,016 Points

yes it takes time to make the network request so it wont be instant. you could add a spinning loading view if you wanted using a UIActivityIndicator