How to update UI of a view from another view [ SwiftUI Question] - swift

Question

I am new to Swift & iOS dev in general.
I am building an app in SwiftUI. Assume there are 2 separate views in different files: MainView() & Results() and TabBar()(ignore the naming, this is just an example)(those 2 views are ON 2 SEPARATE TABS)
My goal is to press on that button FROM ResultsView() and change the textValue property of MainView() to something else & then display the change ON the MainView(). How can I do that? P.S Please ignore alignment & etc. I am new to StackOverflow
struct MainView: View {
#State var textValue: String = "Old Text"
var body: some View {
Text(textValue)
}
}
struct TabBar: View {
var body: some View {
TabView {
MainView()
.tabItem {
Label("Main", systemImage: "circle.dashed.inset.filled")
}
ResultsView()
.tabItem {
Label("Results", systemImage: "person.2.crop.square.stack.fill")
}
}
}
}
struct ResultsView: View {
var body: some View {
Button {
// HOW TO UPDATE MainView.textValue?
} label: {
Text("Update")
}
}
}
ContentView() just has TabBar() in body
Basically, my question is how do we change UI of certain view from another view? Without NavigationLink
Might sound like a rookie question, but any reply will be so appreciated!

Answer 1

You can achieve this by passing the textValue from MainView to DetailView through a #Binding.
struct MainView: View {
#State private var text: String = "Original"
var body: some View {
NavigationView {
VStack {
Text(text)
NavigationLink("Detail", destination: DetailView(text: $text))
}
}
}
}
struct DetailView: View {
#Binding var text: String
var body: some View {
Button("Change Text") {
text = "New Text"
}
}
}
I recommend you read this article about bindings as it explains how to change a view from elsewhere.
Edit:
Because you mentioned, that both views are in a TabBar, here should be a working example:
struct ContentView: View {
#State private var text: String = "Original Text"
var body: some View {
TabView {
MainView(text: $text)
.tabItem { ... }
DetailView(text: $text)
.tabItem { ... }
}
}
}
struct MainView: View {
#Binding var text: String
var body: some View {
Text(text)
}
}
struct DetailView: View {
#Binding var text: String
var body: some View {
Button("Change Text") {
text = "New Text"
}
}
}