Drag and drop in collectionView with data - arrays

Question

I'm trying to add drag and drop to my collectionView, and I have some issues;
When I drag my cell, the data disappear (UITextField). I think I don't save the data in my dataArray correctly...
And the second issue: the drag and drop "works" (without data lol) in the collectionView where I create the cell, but I can't drag this cell to another collection view. The animation is play, but I can't perform a drop.
this I my code:
fist, my class Task, my dataArray is of this type:
class Task: NSObject, Codable, NSItemProviderReading, NSItemProviderWriting {
var task: String?
var button: Bool?
init(task: String, button: Bool) {
self.task = task
self.button = button
}
static var writableTypeIdentifiersForItemProvider: [String] {
return [(kUTTypeData) as String]
}
func loadData(withTypeIdentifier typeIdentifier: String, forItemProviderCompletionHandler completionHandler: #escaping (Data?, Error?) -> Void) -> Progress? {
let progress = Progress(totalUnitCount: 100)
do {
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
let data = try encoder.encode(self)
let json = String(data: data, encoding: String.Encoding.utf8)
progress.completedUnitCount = 100
completionHandler(data, nil)
} catch {
completionHandler(nil, error)
}
return progress
}
static var readableTypeIdentifiersForItemProvider: [String] {
return [(kUTTypeData) as String]
}
static func object(withItemProviderData data: Data, typeIdentifier: String) throws -> Self {
let decoder = JSONDecoder()
do {
let myJSON = try decoder.decode(Task.self, from: data)
return myJSON as! Self
} catch {
fatalError("Err")
}
}
Here I try to save my data and perform drag and drop:
extension LTHM_Todo: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MyCollectionViewCell.identifier, for: indexPath as IndexPath) as! MyCollectionViewCell
cell.myText.text = dataArray[indexPath.row].task
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 300, height: 40)
}
func collectionView(_ collectionView: UICollectionView, canMoveItemAt indexPath: IndexPath) -> Bool {
return true
}
public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return dataArray.count
}
private func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MyCollectionViewCell.identifier, for: indexPath as IndexPath) as! MyCollectionViewCell
return cell
}
extension LTHM_Todo: UICollectionViewDragDelegate, UICollectionViewDropDelegate {
func collectionView(_ collectionView: UICollectionView, dropSessionDidUpdate session: UIDropSession, withDestinationIndexPath destinationIndexPath: IndexPath?) -> UICollectionViewDropProposal
{
if session.localDragSession != nil
{
if collectionView.hasActiveDrag
{
return UICollectionViewDropProposal(operation: .move, intent: .insertAtDestinationIndexPath)
}
else
{
return UICollectionViewDropProposal(operation: .copy, intent: .insertAtDestinationIndexPath)
}
}
else
{
return UICollectionViewDropProposal(operation: .forbidden)
}
func collectionView(_ collectionView: UICollectionView, performDropWith coordinator: UICollectionViewDropCoordinator)
{
let destinationIndexPath: IndexPath
if let indexPath = coordinator.destinationIndexPath
{
destinationIndexPath = indexPath
}
else
{
let section = collectionView.numberOfSections - 1
let row = collectionView.numberOfItems(inSection: section)
destinationIndexPath = IndexPath(row: row, section: section)
}
switch coordinator.proposal.operation
{
case .move:
reorderItem(coordinator: coordinator, destinationIndexPath: destinationIndexPath, collectionView: collectionView)
break
default:
return
}
}
fileprivate func reorderItem(coordinator: UICollectionViewDropCoordinator, destinationIndexPath: IndexPath, collectionView: UICollectionView) {
let items = coordinator.items
if items.count == 1, let item = items.first, let sourceIndexPath = item.sourceIndexPath
{
var dIndexPath = destinationIndexPath
if dIndexPath.row >= collectionView.numberOfItems(inSection: 0)
{
dIndexPath.row = collectionView.numberOfItems(inSection: 0) - 1
}
collectionView.performBatchUpdates({
self.dataArray.remove(at: sourceIndexPath.row)
self.dataArray.insert(item.dragItem.localObject as! Task, at: dIndexPath.row)
collectionView.deleteItems(at: [sourceIndexPath])
collectionView.insertItems(at: [dIndexPath])
})
coordinator.drop(item.dragItem, toItemAt: dIndexPath)
}
}
func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
let item = self.dataArray[indexPath.row]
let itemProvider = NSItemProvider(object: item)
let dragItem = UIDragItem(itemProvider: itemProvider)
dragItem.localObject = item
return [dragItem]
}