Display subview from an array in SwiftUI - view

Question

I am trying to present a sequence of Views, each gathering some information from the user. When users enter all necessary data, they can move to next View. So far I have arrived at this (simplified) code, but I am unable to display the subview itself (see first line in MasterView VStack{}).
import SwiftUI
protocol DataEntry {
var entryComplete : Bool { get }
}
struct FirstSubView : View, DataEntry {
#State var entryComplete: Bool = false
var body: some View {
VStack{
Text("Gender")
Button("Male") {
entryComplete = true
}
Button("Female") {
entryComplete = true
}
}
}
}
struct SecondSubView : View, DataEntry {
var entryComplete: Bool {
return self.name != ""
}
#State private var name : String = ""
var body: some View {
Text("Age")
TextField("Your name", text: $name)
}
}
struct MasterView: View {
#State private var currentViewIndex = 0
let subview : [DataEntry] = [FirstSubView(), SecondSubView()]
var body: some View {
VStack{
//subview[currentViewIndex]
Text("Subview placeholder")
Spacer()
HStack {
Button("Prev"){
if currentViewIndex > 0 {
currentViewIndex -= 1
}
}.disabled(currentViewIndex == 0)
Spacer()
Button("Next"){
if (currentViewIndex < subview.count-1){
currentViewIndex += 1
}
}.disabled(!subview[currentViewIndex].entryComplete)
}
}
}
}
I do not want to use NavigationView for styling reasons. Can you please point me in the right direction how to solve this problem? Maybe a different approach?

Answer 1

One way to do this is with a Base View and a switch statement combined with an enum. This is a similar pattern I've used in the past to separate flows.
enum SubViewState {
case ViewOne, ViewTwo
}
The enum serves as a way to easily remember and track which views you have available.
struct BaseView: View {
#EnvironmentObject var subViewState: SubViewState = .ViewOne
var body: some View {
switch subViewState {
case ViewOne:
ViewOne()
case ViewTwo:
ViewTwo()
}
}
}
The base view is a Container for the view control. You will likely add a view model, which is recommended, and set the state value for your #EnvironmentObject or you'll get a null pointer exception. In this example I set it, but I'm not 100% sure if that syntax is correct as I don't have my IDE available.
struct SomeOtherView: View {
#EnvironmentObject var subViewState: SubViewState
var body: some View {
BaseView()
Button("Switch View") {
subViewState = .ViewTwo
}
}
}
This is just an example of using it. You can access your #EnvironmentObject from anywhere, even other views, as it's always available until disposed of. You can simply set a new value to it and it will update the BaseView() that is being shown here. You can use the same principle in your code, using logic, to determine the view to be shown and simply set its value and it will update.