How do you edit the members of a Struct of type View from another Struct of type View? (SwiftUI) - swift

Question

I have the following 2 structs within separate files and displayed in the contentView. What I'm trying to understand is how to maintain the contentView as only displaying and organizing the UI. Placing all of my other views in separate files. My first thought was the correct approach would be to use static variables updated by functions that are called from the button press action. But the buttons text did not update accordingly. As they are dynamically updated according to #State.
update:
I attempted to solve this by using protocols and delegates to no avail. By my understanding this delegate call should be receiving on the other end and updating structcop.ID and the change should be reflected in the content view.
FILE 1
import SwiftUI
struct structdispatch: View {
var radio:RadioDelegate?
func send() {
radio?.update()
self.debug()
}
var body: some View {
Button(action: self.send)
{Text("DISPATCHER")}
}
func debug() {
print("Button is sending?")
}
}
struct structdispatch_Previews: PreviewProvider {
static var previews: some View {
structdispatch()
}
}
**FILE 2:**
import SwiftUI
protocol RadioDelegate {
func update()
}
struct structcop: View, RadioDelegate {
#State public var ID:Int = 3
func update(){
print("message recieved")
self.ID += 1
print(self.ID)
}
var body: some View {
Text(String(self.ID))
}
}
struct structcop_Previews: PreviewProvider {
static var previews: some View {
structcop()
}
}
DEBUG CONSOLE RETURNS:
The Button is working

Answer 1

View is updated on some internal DynamicProperty change, like #State, so here is possible solution
Tested with Xcode 12 / iOS 14
struct structcop: View {
static public var ID = 3
#State private var localID = Self.ID {
didSet {
Self.ID = localID
}
}
var body: some View {
Button(action: printme)
{Text(String(localID))}
}
func printme(){
self.localID = 5
print(structcop.ID)
}
}

Answer 2

Solution:
After some digging I have a working solution but I'm still curious if there is a way to modify properties of other structs while maintaining dynamic view updates.
Solution: store data for display in an observable object which will either read or act as the model which the user is interacting with.
An observable object is a custom object for your data that can be bound to a view from storage in SwiftUI’s environment. SwiftUI watches for any changes to observable objects that could affect a view, and displays the correct version of the view after a change. -apple
A new model type is declared that conforms to the ObservableObject protocol from the Combine framework. SwiftUI subscribes to the observable object and updates relevant views that need refreshing when the data changes. SceneDelegate.swift needs to have the .environmentObject(_:) modifier added to your root view.
Properties declared within the ObservableObject should be set to #Published so that any changes are picked up by subscribers.
For test code I created an ObservableObject called headquarters
import SwiftUI
import Combine
final class hq: ObservableObject {
#Published var info = headQuarters
}
let headQuarters = hqData(id: 3)
struct hqData {
var id: Int
mutating func bump() {
self.id += 1
}
}
In my struct dispatch I subscribed to the object and called a function that iterated the id in the model whenever the button was pressed. My struct cop also subscribed to the object and thus the model and button text updated accordingly to changes.
struct dispatch: View {
#EnvironmentObject private var hq: headqarters
var body: some View {
Button(action: {self.hq.info.bump()}) {
Text("Button")
}
}
}
struct cop: View {
#EnvironmentObject private var hq: headquarters
var body: some View {
Text(String(self.hq.info.id))
}
}