How to recovery dataSource after disposed from a catchError - ios

Question

I have one UITableView populated by reactive viewmodel using RxSwift, pagination and refresh are working well. The viewModel.dataSource() is consuming my API and sometime I can receive a empty result parsed as error type.
I want to catch this error and create an empty state, hiding tableview and showing a emptyViewState. I thought I could make it with the catchError.
My problem is after catchError, the dataSource is disposed and I couldn't be able to recovery the empty state and repopulated the tableview, I tried to recreate the dataSource calling self.bindDataSource() but I getting fatal error.
There is a way to avoid dataSource disposed ? How can I reconnect / rebuild the dataSource to recovery from the empty state ?
class MyViewControl: UIViewController {
fileprivate let disposeBag = DisposeBag()
fileprivate let viewModel = ViewModel()
let dataSource = SearchViewModel.SearchDataSource()
#IBOutlet fileprivate weak var tableView: UITableView!
#IBOutlet weak var emptyStateView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
// When I disable tableview, can see a hidden view with empty state message and one button
viewModel.isTableViewHidden
.bindTo(tableView.rx.isHidden)
.addDisposableTo(disposeBag)
self.setupTableView()
}
fun setupTableView() {
// ... setup table view
self.bindDataSource()
}
fileprivate func bindDataSource() {
// Bind dataSource from search to UITableView
viewModel.dataSource()
.debug("[DEBUG] Loading Search Tableview ")
.bindTo( tableView.rx.items(dataSource: dataSource) )
.addDisposableTo( disposeBag )
}
#IBAction fileprivate func emptyStateAction(_ sender: UIButton) {
// Do something and try to recreate the bindDataSource
self.bindDataSource()
}
}
class SearchViewModel {
private let disposeBag = DisposeBag()
typealias SearchDataSource = RxTableViewSectionedReloadDataSource<PaginationStatus<WorkerEntity>>
let isTableViewHidden = BehaviorSubject<Bool>(value: false)
// Controls to refresh and paging tableview
let refreshTrigger = BehaviorSubject<Void>(value:())
let nextPageTrigger = PublishSubject<Void>()
// Others things happing herer
func dataSource() -> Observable<[PaginationStatus<WorkerEntity>]> {
return self.refreshTrigger.debug("[DEBUG] Refreshing dataSource")
.flatMapLatest { [unowned self] _ -> Observable<[PaginationStatus<WorkerEntity>]> in
// Access the API and return dataSource
}
.catchError { [unowned self] error -> Observable<[PaginationStatus<WorkerEntity>]> in
// Hidden the tableview
self.isTableViewHidden.onNext(true)
// Do others things
return Observable.of([PaginationStatus.sectionEmpty])
}
}
}

Answer 1

when you bindDataSource() you dont reinitialised your datasource, so you bind it to a error event.
You need to init it, to bind it again. And you might want to remove your binding too
let disposeBagTableView = DisposeBag()
//remove
let dataSource = SearchViewModel.SearchDataSource()
fileprivate func bindDataSource() {
// Bind dataSource from search to UITableView
disposeBagTableView = DisposeBag()
SearchViewModel.SearchDataSource()
.debug("[DEBUG] Loading Search Tableview ")
.bindTo( tableView.rx.items(dataSource: dataSource) )
.addDisposableTo( disposeBagTableView )
}