Not able to reload data properly when retrieving objects from Parse

Question

I am retrieving data from "_User" class this way:

my declarations ..

 var userIds = [String]()
 var userNames = [String]()
 var profilePics = [PFFile]()
 var gender = [String]()


var userQuery = PFUser.query()
        userQuery?.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in

            if let objects = objects {

                self.userIds.removeAll(keepCapacity: true)
                self.userNames.removeAll(keepCapacity: true)
                self.profilePics.removeAll(keepCapacity: true)

                for object in objects {

                    if let user = object as? PFUser {
                        if user.objectId != PFUser.currentUser()?.objectId {

                            self.userIds.append(object["objectId"] as! userListTableViewCell)  // getting an error here..  "unexpectedly found nil while unwrapping an Optional value"
                            self.userNames.append(object["fullName"] as! String!)
                            self.profilePics.append(object["profilePicture"] as! PFFile!)
                            self.gender.append(object["gender"] as! String!)

                        }


                    }
                    self.tableView.reloadData()
                }


            }




        })

]1

here when i click on follow button for user "Rfdfbd" then automatically the "unfollow" title appears on user "Ihbj....." also :/ how can i fix this??

my IBAction followButton code is here:

@IBAction func followButtonTapped(sender: UIButton) {

    println(sender.tag)

    sender.setTitle("unfollow", forState: UIControlState.Normal)

    let getOjbectByIdQuery = PFUser.query()
    getOjbectByIdQuery!.whereKey("objectId", equalTo: userIds[sender.tag])
    getOjbectByIdQuery!.getFirstObjectInBackgroundWithBlock { (foundObject: PFObject?, error: NSError?) -> Void in

        if let object = foundObject {

            var followers:PFObject = PFObject(className: "Followers")
            followers["user"] = object
            followers["follower"] = PFUser.currentUser()
            followers.saveEventually()

        }
    }
}

I am using sender.tag for the follow button here..

This seems you have same button reference in different cells.That's why you update the button contents it effects all the places of button reference. — Vishnuvardhan
– Vishnuvardhan, Commented Jul 31, 2015 at 5:34

Kyle H · Accepted Answer · 2015-07-31 21:32:30Z

1

I've had this problem before and fixed it by embedding a button in each cell. Inside your UITableView you should try embedding each cell with a UIButton.

First make a custom UITableViewCell in a separate file. Then drag and make an IBOutlet for your UIButton inside your custom cell.

class MyCustomCell: UITableViewCell{
    @IBOutlet weak var followButton: UIButton!
    var isFollowing:Bool = false
    //Declare other cell attributes here like picture, name, gender
    // ......
}

When you query and gather the data for your cells, you can store them in an array in your UITableViewController. For example, var myCellArray = [MyCustomCell](). Then your UITableViewController will look something like this:

var myCellArray = [userListTableViewCell]()

override func viewDidLoad(){
    super.viewDidLoad()

    var userQuery = PFUser.query()
    userQuery.findObjectsInBackgroundWithBlock({ (objects: [AnyObject]?, error: NSError?) -> Void in

        if let usersArray = objects as! [PFUser] {

            self.myCellArray.removeAll(keepCapacity: false)

            for user in usersArray {

                if let user = object as? PFUser {
                    if user.objectId != PFUser.currentUser()?.objectId {
                        var myCell = userListTableViewCell()
                        myCell.userID = user.objectId
                        myCell.username = user["fullName"] as! String
                        myCell.gender = user["gender"] as! String

                        var userPicture = user["profilePicure"] as? PFFile
                        var image = UIImage(data:userPicture!.getData()!)
                        myCell.displayPicture.image = image

                        myCellArray.append(myCell)
                        self.tableView.reloadData()

                    }
                }
            }
        }
    })
}


override func tableView(tableView: UITableView, moveRowAtIndexPath sourceIndexPath: NSIndexPath, toIndexPath destinationIndexPath: NSIndexPath) {
    myCellArray.count
}


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

    var cell = tableView.dequeueReusableCellWithIdentifier("CellIdentifier") as! userListTableViewCell

    //Edit the storyboard labels for each cell:
    cell.username.text = myCellArray[indexPath.row].username
    // etc....

    //Embed a button with each cell
    cell.followButton.layer.setValue(indexPath.row, forKey: "index")
    cell.followButton.addTarget(self, action: "followButtonTapped:", for ControlEvents: UIControlEvents.TouchUpInside)

    if (myCellArray[indexPath.row].isFollowing == false){
        cell.followButton.setTitle("Follow", forState: .Normal)
    }else{
        cell.followButton.setTitle("Unfollow", forState: .Normal)
    }
    return cell
}

func followButtonTapped(sender: UIButton){
    let cellIndex : Int = (sender.layer.valueForKey("index")) as! Int
    //You now have the index of the cell whose play button was pressed so you can do something like
    if (myCellArray[cellIndex].isFollowing == false){
        myCellArray[cellIndex] = true
    }else{
        myCellArray[cellIndex] = false
    }
    self.tableView.reloadData()
}

edited Jul 31, 2015 at 21:32

answered Jul 31, 2015 at 18:39

Kyle H

9211 gold badge8 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

31 Comments

Akshay Kheveria Over a year ago

can you elucidate "var myCellArray = [MyCustomCell]()" more??

Kyle H Over a year ago

You would create this inside your UITableViewController class before your functions. On viewDidLoad you should do your Parse query and loop through each PFObject in your Parse class. Inside the loop you can create a MyCustomCell and give it the properties from your Parse query. When you're done with your query, call self.tableView.reloadData() to load your cells.

Akshay Kheveria Over a year ago

i've made var userIds = [userListTableViewCell]() and i am getting error here.. self.userIds.append(object.objectId as String!) in my query and rest of the PFObjects by the other arrays i've explained.. like usernames, profilePics, gender.. :/ What am i doing wrong.??

Kyle H Over a year ago

Try using query.findObjectsInBackgroundWithBlock({ (objects: [AnyObject]?, error: NSError?) -> Void in }) function when you do your query. That way you are getting an array of your objects to loop through

Kyle H Over a year ago

Your edited query does not match the declaration I just gave you. You're not getting objects array from your query.

|

Collectives™ on Stack Overflow

Not able to reload data properly when retrieving objects from Parse

1 Answer 1

31 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

31 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related