Sharing common variables within a Container View - swiftui

Question

Scenario:
I had a large view that I want to break up into a container view having couple of child views.
So each view has its own .string file.
The paradigm: dissemination of processes from one file to the children as a 'collective'.
The container view would act as the hub, the intelligence.
I don't want this to be overly complicated; merely modularizing the logic in discrete parts for easy maintenance.
Problem: I can only go one-way #State ---> #Binding between struct Views without going thru a Class Object.
Is there a way to return values; e.g., two-way data exchange?
That is, child views sharing their common views with the parent/container?
View1 | View2 & View2 | View1 <br/>
#State -->#Binding (data) & #Binding <-- #State (result)?
I must I use some sort of singleton class object for the data exchange?
Again, I'm for simplicity of design vs a large single struct View.

Answer 1

Binding is the way a value is "returned" from a child to parent. If the child didn't update the value (i.e. just one-way parent -> child, then you wouldn't need a binding - just pass the variable in an init).
struct Child: View {
#Binding var num: Int
var body: some View {
VStack {
Text("\(num)")
Button("increase") { self.num += 1 }
}
}
}
struct Parent: View {
#State var sharedNum: Int = 0
var body: some View {
VStack {
Text("\(sharedNum)")
Child(num: $sharedNum)
Child(num: $sharedNum)
}
.onChange(of: sharedNum) { print("shared num", $0) } // iOS14 required
}
}
Both children and the parent would display the same number regardless of which of the children changed it.
But, sometimes a child might need to notify the parent not necessarily through a value change. Then you could use a callback:
struct Child: View {
var onClick: (Int) -> Void
var body: some View {
Button("generate random") {
onClick(Int.random(1...100))
}
}
}
struct Parent: View {
var body: some View {
Child {
print("new random", $0)
}
}
}