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A simple implementation of UITableViewDescriptor.
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class UITableViewDescriptor: NSObject { | |
var tableView: UITableView? { | |
didSet { | |
configureBindings() | |
} | |
} | |
private var dataSource: UITableViewDiffableDataSource<Int, AnyHashable>! | |
private var sections = [UITableViewSection]() | |
private let sectionsPublisher: AnyPublisher<[UITableViewSection], Never> | |
private var subscriptions = Set<AnyCancellable>() | |
convenience init(sections: [UITableViewSection]) { | |
self.init(sections: Just(sections).eraseToAnyPublisher()) | |
} | |
init<T: Publisher>(sections: T) where T.Output == [UITableViewSection], T.Failure == Never { | |
self.sectionsPublisher = sections.eraseToAnyPublisher() | |
} | |
func updateSnapshot() { | |
var snapshot = NSDiffableDataSourceSnapshot<Int, AnyHashable>() | |
snapshot.appendSections(sections.map { $0.sectionIndex }) | |
for section in sections { | |
snapshot.appendItems(section.items, toSection: section.sectionIndex) | |
} | |
dataSource.apply(snapshot, animatingDifferences: true) | |
} | |
private func configureBindings() { | |
guard let tableView = self.tableView else { return } | |
dataSource = UITableViewDiffableDataSource<Int, AnyHashable>( | |
tableView: tableView, | |
cellProvider: {(tableView, indexPath, data) in | |
self.sections[indexPath.section].cellForRow(in: tableView, indexPath: indexPath) | |
} | |
) | |
tableView.dataSource = self.dataSource | |
sectionsPublisher.sink { | |
self.sections = $0 | |
self.sections.enumerated().forEach { $1.attach(to: self, sectionIndex: $0) } | |
self.updateSnapshot() | |
}.store(in: &subscriptions) | |
} | |
} | |
extension UITableViewDescriptor: UITableViewDelegate { | |
func numberOfSections(in tableView: UITableView) -> Int { | |
sections.count | |
} | |
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { | |
sections[section].numberOfRows() | |
} | |
} |
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