See sample code below...
Basically it's a galleryView with a dataSource that can add/remove items dynamically. It works as expected when GalleryView's dataSource variable has a type (that conforms to ObservableObject)
However when I change dataSource's type to be a protocol, I can't seem to get my code to compile.
Any guidance on how to use a protocol in GalleryView, and continue to keep the UI updating when the model object's item list changes?
thanks!
Mike
protocol GalleryDataSource: ObservableObject {
var itemCount: Int { get }
func item(for index: Int) - String
}
class GalleryModel: ObservableObject {
static let test1: GalleryModel = GalleryModel(items: ["A","B","C"])
@Published var items: [String]
init(items: [String]) {
self.items = items
}
}
extension GalleryModel: GalleryDataSource {
var itemCount: Int {
return items.count
}
func item(for index: Int) - String {
return items[index]
}
}
struct ContentView: View {
var model: GalleryModel = GalleryModel.test1
var body: some View {
VStack {
GalleryView(dataSource: model)
Button("Add Item") {
model.items.append("\(model.items.count)")
}
}
}
}
struct GalleryView: View {
@ObservedObject var dataSource: GalleryModel //GalleryDataSource
var body: some View {
ScrollView(.horizontal, content: {
HStack {
ForEach(0..self.dataSource.itemCount, id:\.self) { index in
Text(dataSource.item(for: index))
.padding()
}
}
})
}
}
