Binding to a UIRefreshControl after network call - ios

Question

I am new to RxSwift and I was wondering how I would be able to "reactively" use a UIRefreshControl with a UITableView instead of the normal way of creating a target, and manually calling beginRefreshing() and endRefreshing().
For instance, say I am loading some strings from an API:
class TableViewController: UITableViewController {
var data : [String] = []
let db = DisposeBag()
override func viewDidLoad() {
super.viewDidLoad()
refreshControl = UIRefreshControl()
//I don't want to use
//refreshControl?.addTarget(self, action: #selector(getData), forControlEvents: .ValueChanged)
//Do something to refreshControl.rx_refreshing?
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
let str = data[indexPath.row]
cell.textLabel?.text = str
return cell
}
//MARK: - Requests
private func getData() {
let myData = MyAPI.getData() //Returns Observable<[String]>
myData
.subscribe({ [weak self] (event) in
switch event {
case .Next(let strings):
self?.data = strings
self?.tableView.reloadData()
break
case .Error(let err):
print(err)
break
case .Completed:
break
}
// self?.refreshControl?.endRefreshing()
})
.addDisposableTo(db)
}
}
MyAPI sends a request for some string values, how can I bind the refreshControl to call getData() and also stop refreshing when it's finished (or error'd) the network request? Do I need to bind to refreshControl.rx_refreshing?

Answer 1

RxSwift's example app provides an interesting class to handle this kind of logic: ActivityIndicator.
Once you have ActivityIndicator in, code for binding rx_refreshing to the request becomes really easy.
let activityIndicator = ActivityIndicator()
override func viewDidLoad() {
super.viewDidLoad()
refreshControl = UIRefreshControl()
// When refresh control emits .ValueChanged, start fetching data
refreshControl.rx_controlEvent(.ValueChanged)
.flatMapLatest { [unowned self] _ in
return self.getData()
.trackActivity(activityIndicator)
}
.subscribeNext { [unowned self] strings in
self.data = strings
self.tableView.reloadData()
}
.addDisposableTo(db)
// Bind activity indicator true/false to rx_refreshing
activityIndicator.asObservable()
.bindTo(refreshControl.rx_refreshing)
.addDisposableTo(db)
}
// getData only needs to return an observable, subscription is handled in viewDidLoad
private func getData() -> Observable<[String]> {
return myData = MyAPI.getData() //Returns Observable<[String]>
}