bobgodwinx

/// Now composing our `MVVM`
/// just like a plug and play

/// `Model`
let provider = ContactProvider()
/// `ViewModel`
let viewModel = ContactViewModel(provider)
/// `View`
let viewController = ContactViewController(viewModel)

bobgodwinx

/// `ContactViewController` = `View`
class ContactViewController: UIViewController {
    private let bag = DisposeBag()
    let viewModel: Contactable
    
    /// `dependency inversion`
    init(_ viewModel: Contactable) {
        self.viewModel = viewModel
        super.init(nibName: nil, bundle: nil)
        configure()

bobgodwinx

/// `ContactViewModel` = `ViewModel`
class ContactViewModel: Contactable {

    let datasource: Driver<[TableDatasource.Section]>
    /// `dependency inversion`
    init(_ provider: ContactProviderType) {
        self.datasource = provider
            .contacts
            .map { items -> [TableDatasource.Section] in
                 /// groupedByNationality = [Nationality: [Person]]` ///new feature in swift 4.x

bobgodwinx

/// `TableDatasource`
class TableDatasource: NSObject, UITableViewDataSource, RxTableViewDataSourceType, SectionedViewDataSourceType, UITableViewDelegate {
    struct Section {
        let title: String
        let rows: [TableRow]

        init(title: String, rows: [TableRow]) {
            self.title = title
            self.rows = rows
        }

bobgodwinx

/// `Contactable` = `ViewModel` requirement
protocol Contactable {
    var datasource: Driver<[TableDatasource.Section]> {get}
}

bobgodwinx

/// `ContactProvider` = `Model`
class ContactProvider: ContactProviderType {
    let contacts: Observable<Set<Person>>

    init() {
        /// Only Leader and the richest
        /// Disclaimer this data is just
        /// for example purposes. I am not
        /// responsible for any incorrect
        /// information. I hereby declare

bobgodwinx

/// `ContactProviderType` = `Model` requirement
protocol ContactProviderType {
    /// Set that contains `Person`
    var contacts: Observable<Set<Person>> {get}
}

bobgodwinx

/// `Person`
struct Person: Hashable {
    let firstName: String
    let lastName: String
    let age: Int
    let nationality: Nationality
}

bobgodwinx

//MARK: Two-way Bindings
extension ControlProperty {
    func twoWayBindTo(_ variable: Variable<E>) -> Disposable {
        let bindUI = variable.asObservable().bind(to: self)
        let bindVariable = subscribe(
            onNext: {value in
                variable.value = value
        }, onCompleted: {
            bindUI.dispose()
        })

bobgodwinx

/// Usage of shadowed protocol styled type erasure
let rows: [TableRow] = [ProductCell(name: "Hello"), ItemCell(id: "123456")]

for row in rows {
    if let cell = row as? ProductCell {
        cell.configure(with: Product())
    }

    if let cell = row as? ItemCell {
        cell.configure(with: Item())