Inserting one item into a collection reloads EVERY single item inside the collectionView

Question

I've reduced my code to just a dozen lines for the sake of this question. I linked fetchedResultsController to the jsqMessagesViewController framework.

What the app does is when you press the send button, it inserts an object into context, which activates .Insert of fetchedResultsController.

For some reason, every time I insert into the collection View it reloads every single thing in the collection view. This is causing a TON of bugs, and I can't tell if it's something I'm doing wrong, if its the JSQ framework itself, or if this is normal?

Anyways, here is my entire code. It is not long, and if you're familiar code data in swift, this should be a breeze for you to read.

class ChatController: JSQMessagesViewController, NSFetchedResultsControllerDelegate {

    let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

    lazy var fetchedResultsControler: NSFetchedResultsController<NSFetchRequestResult> = {

        let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Message")
        fetchRequest.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)]
        let frc = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.context, sectionNameKeyPath: nil, cacheName: nil)
        frc.delegate = self
        return frc
    }()

func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
    if type == .insert {   
            collectionView.insertItems(at: [newIndexPath!])
            scrollToBottom(animated: true)
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.senderId = ""
    self.senderDisplayName = ""

    do {   
        try fetchedResultsControler.performFetch()  
    }

    catch { }       
}

override func didPressSend(_ button: UIButton!, withMessageText text: String!, senderId: String!, senderDisplayName: String!, date: Date!) {
    let message = NSEntityDescription.insertNewObject(forEntityName: "Message", into: context) as! Message

    message.text = text
    message.timestamp = Date() as NSDate?      
}

override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageDataForItemAt indexPath: IndexPath!) -> JSQMessageData! {
    let msg : Message = fetchedResultsControler.object(at: indexPath) as! Message
    let messageData = JSQMessage(senderId: senderId, displayName: senderDisplayName, text: msg.text)
    return messageData
}


override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return (fetchedResultsControler.sections?[0].numberOfObjects)!
}

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = super.collectionView(collectionView, cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell
    cell.layer.shouldRasterize = true
    cell.layer.rasterizationScale = UIScreen.main.scale
    return cell
}

override func collectionView(_ collectionView: JSQMessagesCollectionView!, messageBubbleImageDataForItemAt indexPath: IndexPath!) -> JSQMessageBubbleImageDataSource! {
    let bubbleFactory = JSQMessagesBubbleImageFactory()
    return bubbleFactory?.outgoingMessagesBubbleImage(with: .black)
}

override func collectionView(_ collectionView: JSQMessagesCollectionView!, avatarImageDataForItemAt indexPath: IndexPath!) -> JSQMessageAvatarImageDataSource! {
    return nil
}

}

score 0 · Answer 1 · answered Oct 24 '16 at 06:52

0

I am not sure but try if this can help you out.

collectionView?.performBatchUpdates({
            self.collectionView?.reloadItems(at: indexPaths)
        }) { completed in
            //Your Completion Code
            }
        }

answered Oct 24 '16 at 06:52

Deepak Carpenter

1,504
2
10
21

hi Deepak, my problem is not that i want to reload one thing at a time. In fact, I don't want to reload anything. But some reason, inserting an item into the collection is reloading every single other item in the collection view. Which I know is not something that should be happening. – slimboy Oct 24 '16 at 20:07

Inserting one item into a collection reloads EVERY single item inside the collectionView

1 Answers1