/RxPagination

The demo project for "Protocol-Oriented Programming in Networking".

Primary LanguageSwiftMIT LicenseMIT

RxPagination

This is the demo project for my presentation at try! Swift conference 2016.

Set Up

  • carthage bootstrap --platform iOS

Requirements

  • Swift 3.0.1
  • Xcode 8.1

Summary

This demo project illustrates how to use RxSwift, Action and APIKit. The demo app fetches repositories via GitHub search API and displays them using the libraries.

ViewModel

PaginationViewModel<Element> is a view model for pagination. It has an initializer with type parameter Request, which is constrained to conform to PaginationRequest protocol. When PaginationViewModel<Element> is instantiated via init<Request>(baseRequest:), the type of its property that represents pagination elements will be inferred as Observable<[Request.Response.Element]>.

final class PaginationViewModel<Element: Decodable> {
    let loading: Observable<Bool>
    let elements: Observable<[Element]>

    init<Request: PaginationRequest>(baseRequest: Request) where Request.Response.Element == Element {...}
}

ViewController

Once ViewModel is instantiated with a Request type parameter, remained task that ViewController have to do is binding input streams and output streams.

class SearchRepositoriesViewController: UITableViewController {
    @IBOutlet weak var indicatorView: UIActivityIndicatorView!

    let disposeBag = DisposeBag()
    let viewModel = PaginationViewModel(baseRequest:
        GitHubAPI.SearchRepositoriesRequest(query: "Swift"))

    override func viewDidLoad() {
        super.viewDidLoad()

        rx.sentMessage(#selector(viewWillAppear))
            .map { _ in }
            .bindTo(viewModel.refreshTrigger)
            .addDisposableTo(disposeBag)

        tableView.rx.reachedBottom
            .bindTo(viewModel.loadNextPageTrigger)
            .addDisposableTo(disposeBag)

        viewModel.loading
            .bindTo(indicatorView.rx.isAnimating)
            .addDisposableTo(disposeBag)

        viewModel.elements
            .bindTo(tableView.rx.items(cellIdentifier: "Cell")) { _, repository, cell in
                cell.textLabel?.text = repository.fullName
                cell.detailTextLabel?.text = "🌟\(repository.stargazersCount)"
            }
            .addDisposableTo(disposeBag)
    }
}

Contact

Twitter: https://twitter.com/_ishkawa