A framework for UICollectionView and UITableView that provides:
- Extended collection and table view diffable data sources with handlers for selecting, reordering, focusing and editing cells and additional functionality.
- Table view cell registration similar to
UICollectionView.CellRegistration. - Additional extensions for
UICollectionViewandUITableView.
There are handlers for selecting, reordering, focusing and editing cells.
Examples of some of the included handlers:
// Handler that gets called when the user did select an item. diffableDataSource.selectionHandlers.didSelect = { itemIdentifier in } // Handler that gets called when an item/cell is about to be shown. diffableDataSource.displayingHandlers.willDisplay = { itemIdentifier, cell in }TableViewDiffableDataSource provides handlers for reordering cells like the UICollectionViewDiffableDataSource reordering handlers that Apple provides:
// Allow every item to be reordered tableViewDataSource.reorderingHandlers.canReorder = { item in return true } // Update the backing store from the did reorder transaction. tableViewDataSource.reorderingHandlers.didReorder = { [weak self] transaction, _ in guard let self = self else { return } if let updatedCurrentItems = self.currentItems.applying(transaction.difference) { self.currentItems = updatedCurrentItems } }emptyView displays the provided view when the datasource doesn't contain any items:
diffableDataSource.emptyView = myEmptyViewAlternatively you can use emptyContentConfiguration and provide an UIContentConfiguration:
let loadingConfiguration = UIContentUnavailableConfiguration.loading() diffableDataSource.emptyContentConfiguration = loadingConfigurationA registration for the table view’s cells similar to UICollectionView.CellRegistration.
Use a cell registration to register table cell views with your table view and configure each cell for display.
The following example creates a cell registration for cells of type UITableViewCell and string items. Each cells textfield displays its item string.
let cellRegistration = UITableView.CellRegistration<UITableViewCell, String> { cell, indexPath, string in var contentConfiguration = cell.defaultContentConfiguration() contentConfiguration.text = string contentConfiguration.textProperties.color = .lightGray cell.contentConfiguration = contentConfiguration }After you create a cell registration, you pass it in to dequeueConfiguredReusableCell(using:for:item:), which you call from your data source’s cell provider.
dataSource = UITableViewDiffableDataSource<Section, String>(tableView: tableView) { tableView, indexPath, item in return tableView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: item) }Alternatively you can use the UICollectionViewDiffableDataSource and UITableViewDiffableDataSource initializers:
let dataSource = UITableViewDiffableDataSource(tableView: myTableView, cellRegistration: cellRegistration) }A registration for the table view’s header/footer section views.
The following example creates a section view registration for views of type UITableViewHeaderFooterView for sections with strings. Each section header views default content configuration text displays its section string.
let sectionViewRegistration = UITableView.SectionViewRegistration<UITableViewHeaderFooterView, String> { sectionView, indexPath, string in var configuration = sectionView.defaultContentConfiguration() configuration.text = string sectionView.contentConfiguration = configuration }After you create a section view registration, you pass it in to dequeueConfiguredReusableSectionView(using:section:), which you call from your data source’s section header view provider.
dataSource.headerViewProvider = { tableView, section in return tableView.dequeueConfiguredReusableSectionView(using: sectionViewRegistration, section: section) }Alternatively you can also applyHeaderViewRegistration() and `applyFooterViewRegistration()``:
dataSource.applyHeaderViewRegistration(sectionViewRegistration)Options for applying snapshots to a diffable datasource:
// Applies the snapshot animated with default animation duration. dataSource.apply(mySnapshot, .animated) // Applies the snapshot animated with the specified animation duration. dataSource.apply(mySnapshot, .animated(duration: 2.0)) // Applies the snapshot non animated. dataSource.apply(mySnapshot, .withoutAnimation) // Applies the snapshot using reload data. dataSource.apply(mySnapshot, .usingReloadData)