I have a simple TextField that binds to the state 'location' like this,
TextField("Search Location", text: $location)
I want to call a function each time this field changes, something like this:
TextField("Search Location", text: $location) {
self.autocomplete(location)
}
However this doesn't work. I know that there are callbacks, onEditingChanged - however this only seems to be triggered when the field is focussed.
How can I get this function to call each time the field is updated?
You can create a binding with a custom closure, like this:
struct ContentView: View {
@State var location: String = ""
var body: some View {
let binding = Binding<String>(get: {
self.location
}, set: {
self.location = $0
// do whatever you want here
})
return VStack {
Text("Current location: \(location)")
TextField("Search Location", text: binding)
}
}
}
set closure is called three times with every stroke. –
Confiscate From iOS 14, macOS 11, or any other OS contains SwiftUI 2.0, there is a new modifier called .onChange that detects any change of the given state:
struct ContentView: View {
@State var location: String = ""
var body: some View {
TextField("Your Location", text: $location)
.onChange(of: location) {
print($0) // You can do anything due to the change here.
// self.autocomplete($0) // like this
}
}
}
For older iOS and other SwiftUI 1.0 platforms, you can use onReceive:
.onReceive(location.publisher) {
print($0)
}
You can create a binding with a custom closure, like this:
struct ContentView: View {
@State var location: String = ""
var body: some View {
let binding = Binding<String>(get: {
self.location
}, set: {
self.location = $0
// do whatever you want here
})
return VStack {
Text("Current location: \(location)")
TextField("Search Location", text: binding)
}
}
}
Binding that way): I was wondering why if I attach a didSet on the location var the didSet doesn't get called at all. Something like @State var location: String = "" { didSet { //do something }} I don't get why the function doesn't get called. Thank you. –
Fauver set closure is called three times with every stroke. –
Confiscate Another solution, if you need to work with a ViewModel, could be:
import SwiftUI
import Combine
class ViewModel: ObservableObject {
@Published var location = "" {
didSet {
print("set")
//do whatever you want
}
}
}
struct ContentView: View {
@ObservedObject var viewModel = ViewModel()
var body: some View {
TextField("Search Location", text: $viewModel.location)
}
}
Use onReceive:
import Combine
import SwiftUI
struct ContentView: View {
@State var location: String = ""
var body: some View {
TextField("Search Location", text: $location)
.onReceive(Just(location)) { location in
// print(location)
}
}
}
While other answers work might work but this one worked for me where I needed to listen to the text change as well as react to it.
first step create one extension function.
extension Binding {
func onChange(_ handler: @escaping (Value) -> Void) -> Binding<Value> {
Binding(
get: { self.wrappedValue },
set: { newValue in
self.wrappedValue = newValue
handler(newValue)
}
)
}
}
now call change on the binding in TextField something like below.
TextField("hint", text: $text.onChange({ (value) in
//do something here
}))
source : HackingWithSwift
What I found most useful was that TextField has a property that is called onEditingChanged which is called when editing starts and when editing completes.
TextField("Enter song title", text: self.$userData.songs[self.songIndex].name, onEditingChanged: { (changed) in
if changed {
print("text edit has begun")
} else {
print("committed the change")
saveSongs(self.userData.songs)
}
})
.textFieldStyle(RoundedBorderTextFieldStyle())
.font(.largeTitle)
© 2022 - 2024 — McMap. All rights reserved.
Bindingthat way): I was wondering why if I attach a didSet on thelocationvar the didSet doesn't get called at all. Something like@State var location: String = "" { didSet { //do something }}I don't get why the function doesn't get called. Thank you. – Fauver