setting ids on item in Stackview - ios

Question

I have an array of object which I used to create a checkbox. The model has an id, name. I created a stackView to handle checkbox with id now I want to append items of selected checkbox to an array and be able to remove them when deselected. I am able to present all the views and it works well
below is my code
NetworkAdapter.instance.getFeaturesAmeneities()
.subscribe(onNext: {feat in
guard let data = feat.data else {return}
self.features.append(contentsOf: data)
self.stackFeature.axis = .vertical
self.stackFeature.distribution = .fill
self.stackFeature.spacing = 8
data.forEach {
print($0.id)
self.stv = CheckboxStackView()
self.stv?.label.text = $0.name
self.stv?.checkBox.tag = $0.id ?? 0
self.stackFeature.addArrangedSubview(self.stv!)
}
}).disposed(by: disposeBag)
Any help is appreciated

Answer 1

In order to answer this question, we first have to make the stack view reactive and declarative. This means that we have to be able to set the view using a single assignment and that needs to be an observer. This is just like what the RxCocoa library does for UICollectionView, UITableView and UIPickerView.
Writing the function is a bit advanced. First we take the signature from the other views above to define the shape of the function.
func items<Sequence: Swift.Sequence, Source: ObservableType>(_ source: Source) -> (_ viewForRow: #escaping (Int, Sequence.Element, UIView?) -> UIView) -> Disposable where Source.Element == Sequence
The above probably looks daunting. It's a function that takes a source sequence of sequences and returns a function that takes a closure for assembling the views and returns a Dispoable.
The completed function looks like this:
extension Reactive where Base: UIStackView {
func items<Sequence: Swift.Sequence, Source: ObservableType>(_ source: Source) -> (_ viewForRow: #escaping (Int, Sequence.Element, UIView?) -> UIView) -> Disposable where Source.Element == Sequence {
return { viewForRow in
return source.subscribe { event in
switch event {
case .next(let values):
let views = self.base.arrangedSubviews
let viewsCount = views.count
var valuesCount = 0
for (index, value) in values.enumerated() {
if index < viewsCount {
// update views that already exist
_ = viewForRow(index, value, views[index])
}
else {
// add new views if needed
let view = viewForRow(index, value, nil)
self.base.addArrangedSubview(view)
}
valuesCount = index
}
if valuesCount + 1 < viewsCount {
for index in valuesCount + 1 ..< viewsCount {
// remove extra views if necessary
self.base.removeArrangedSubview(views[index])
views[index].removeFromSuperview()
}
}
case .error(let error):
fatalError("Errors can't be allowed: \(error)")
case .completed:
break
}
}
}
}
}
The above can be used like this:
self.stackFeature.axis = .vertical
self.stackFeature.distribution = .fill
self.stackFeature.spacing = 8
let features = NetworkAdapter.instance.getFeaturesAmeneities()
.map { $0.data }
.share(replay: 1)
features
.bind(onNext: { [weak self] in self?.features.append(contentsOf: $0) })
.disposed(by: disposeBag)
features
.bind(to: stackFeature.rx.items) { (row, element, view) in
let myView = (view as? CheckboxStackView) ?? CheckboxStackView()
myView.label.text = element.name
myView.checkBox.tag = element.id ?? 0
return myView
}
.disposed(by: disposeBag)