CollectionViewAdapter

open class CollectionViewAdapter<O> : BaseAdapter<O, DefaultCollectionViewTarget<UICollectionView>>, UICollectionViewDataSource where O : DynamicObject

The DiffableDataSource.CollectionViewAdapter serves as a UICollectionViewDataSource that handles ListPublisher snapshots for a UICollectionView. Subclasses of DiffableDataSource.CollectionViewAdapter may override some UICollectionViewDataSource methods as needed. The DiffableDataSource.CollectionViewAdapter instance needs to be held on (retained) for as long as the UICollectionView‘s lifecycle.

self.dataSource = DiffableDataSource.CollectionViewAdapter<Person>(
    collectionView: self.collectionView,
    dataStack: CoreStoreDefaults.dataStack,
    cellProvider: { (collectionView, indexPath, person) in
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PersonCell") as! PersonCell
        cell.setPerson(person)
        return cell
    }
)

The dataSource can then apply changes from a ListPublisher as shown:

listPublisher.addObserver(self) { [weak self] (listPublisher) in
   self?.dataSource?.apply(
       listPublisher.snapshot,
       animatingDifferences: true
   )
}

DiffableDataSource.CollectionViewAdapter fully handles the reload animations.

Public


                    
                    
                    init(collectionView:dataStack:cellProvider:supplementaryViewProvider:)

Initializes the DiffableDataSource.CollectionViewAdapter. This instance needs to be held on (retained) for as long as the UICollectionView‘s lifecycle.

self.dataSource = DiffableDataSource.CollectionViewAdapter<Person>(
    collectionView: self.collectionView,
    dataStack: CoreStoreDefaults.dataStack,
    cellProvider: { (collectionView, indexPath, person) in
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PersonCell") as! PersonCell
        cell.setPerson(person)
        return cell
    }
)

Declaration

Swift

public init(
    collectionView: UICollectionView,
    dataStack: DataStack,
    cellProvider: @escaping (UICollectionView, IndexPath, O) -> UICollectionViewCell?,
    supplementaryViewProvider: @escaping (UICollectionView, String, IndexPath) -> UICollectionReusableView? = { _, _, _ in nil }
)

Parameters

`collectionView`	the `UICollectionView` to set the `dataSource` of. This instance is not retained by the `DiffableDataSource.CollectionViewAdapter`.
`dataStack`	the `DataStack` instance that the dataSource will fetch objects from
`cellProvider`	a closure that configures and returns the `UICollectionViewCell` for the object
`supplementaryViewProvider`	an optional closure for providing `UICollectionReusableView` supplementary views. If not set, defaults to returning `nil`