so I'm trying to make a search bar that doesn't run the code that displays the results until the user stops typing for 2 seconds (AKA it should reset a sort of timer when the user enters a new character). I tried using .onChange() and an AsyncAfter DispatchQueue and it's not working (I think I understand why the current implementation isn't working, but I'm not sure I'm even attack this problem the right way)...
struct SearchBarView: View {
@State var text: String = ""
@State var justUpdatedSuggestions: Bool = false
var body: some View {
ZStack {
TextField("Search", text: self.$text).onChange(of: self.text, perform: { newText in
appState.justUpdatedSuggestions = true
DispatchQueue.main.asyncAfter(deadline: .now() + 3, execute: {
appState.justUpdatedSuggestions = false
})
if justUpdatedSuggestions == false {
//update suggestions
}
})
}
}
}
The possible approach is to use debounce
from Combine framework. To use that it is better to create separated view model with published property for search text.
Here is a demo. Prepared & tested with Xcode 12.4 / iOS 14.4.
import Combine
class SearchBarViewModel: ObservableObject {
@Published var text: String = ""
}
struct SearchBarView: View {
@StateObject private var vm = SearchBarViewModel()
var body: some View {
ZStack {
TextField("Search", text: $vm.text)
.onReceive(
vm.$text
.debounce(for: .seconds(2), scheduler: DispatchQueue.main)
) {
guard !$0.isEmpty else { return }
print(">> searching for: \($0)")
}
}
}
}