BehaviorRelay in tableviewcell

Question

I'm a beginner to RxSwift so I'll try to explain my scenario... I'm using a UITableView together with RxTableViewSectionedReloadDataSource.

In one of my cells which displays a UITextField I have this:

var observer: BehaviorRelay<String?>! {
    didSet {
        observerDisposable = textField.rx.text.bind(to: observer)
    }
}

Now whenever that cell is selected I display a popup view (not in the cell) where the user can select a date from a UIDatePicker which has a BehaviorRelay<Date?>. So what I want to do is that when the user selects a date I want to update that textfield cell with the selected date.

How would I do this with RxSwift?

Answer 1

First things first, Observables, Subjects and Relays should never be in a var, they should always be lets.

Now to solve your problem... I would expect to see code that is something like this:

let dateText = PublishSubject<String>()

let date = tableView.rx.itemSelected
    .filter(isDateTableView)
    .flatMapFirst { [unowned self] (_) -> Driver<Date> in self.getDate() }

date
    .map { dateFormatter.string(from: $0) }
    .bind(to: dateText)
    .disposed(by: disposeBag)

let dataSource = RxTableViewSectionedReloadDataSource<SectionModel<String, Int>>(configureCell: { dataSource, tableView, indexPath, item in
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! ExampleTableViewCell
    if isDateTableView(indexPath) {
        dateText
            .bind(to: cell.textField.rx.text)
            .disposed(by: cell.disposeBag)
    }
    return cell
})

Driver.just([SectionModel<String, Int>(model: "test", items: [12])])
    .drive(tableView.rx.items(dataSource: dataSource))
    .disposed(by: disposeBag)

All of the above code (including the definition of dateText) would go into your viewDidLoad or a function that viewDidLoad calls.