SwiftUI - stack multiple method calls in parent view - swift

Question

I am kind of a SwiftUI newbe but my question is essentially this:
I have a view that looks like this:
struct myView: View {
var label = Text("label")
var subLabel = Text("sublabel")
var body: some View {
VStack {
label
subLabel
}
}
public func primaryColor(color: Color) -> some View {
var view = self
view.label = view.label.foregroundColor(color)
return view.id(UUID())
}
public func secondaryColor(color: Color) -> some View {
var view = self
view.subLabel = view.subLabel.foregroundColor(color)
return view.id(UUID())
}
}
And here is my problem:
In my parent view, I would like to call myView as follows
struct parentView: View {
var body: some View {
myView()
.primaryColor(color: .red)
.secondaryColor(color: .blue)
}
}
Using only one of these modifiers works fine but stacking them won't work (since they return some View ?).
I don't think that I can use standard modifiers since I have to access myView variables, which (I think) wouldn't be possible by using a ViewModifier.
Is there any way to achieve my goal or am I going on the wrong direction ?

Answer 1

Here is a solution for you - remove .id (it is really not needed, result will be a copy anyway):
struct myView: View {
var label = Text("label")
var subLabel = Text("sublabel")
var body: some View {
VStack {
label
subLabel
}
}
public func primaryColor(color: Color) -> Self {
var view = self
view.label = view.label.foregroundColor(color)
return view
}
public func secondaryColor(color: Color) -> Self {
var view = self
view.subLabel = view.subLabel.foregroundColor(color)
return view
}
}
and no changes in parent view
Demo prepared with Xcode 13 / iOS 15

Answer 2

I'd suggest a refactor where primaryColor and secondaryColor can be passed as optional parameters to your MyView (in Swift, it is common practice to capitalize type names):
struct MyView: View {
var primaryColor : Color = .primary
var secondaryColor : Color = .secondary
var body: some View {
VStack {
Text("label")
.foregroundColor(primaryColor)
Text("sublabel")
.foregroundColor(secondaryColor)
}
}
}
struct ParentView: View {
var body: some View {
MyView(primaryColor: .red, secondaryColor: .blue)
}
}
This way, the code is much shorter and more simple, and follows the general form/practices of SwiftUI.
You could also use Environment keys/values to pass the properties down, but this takes more code (shown here for just the primary color, but you could expand it to secondary as well):
private struct PrimaryColorKey: EnvironmentKey {
static let defaultValue: Color = .primary
}
extension EnvironmentValues {
var primaryColor: Color {
get { self[PrimaryColorKey.self] }
set { self[PrimaryColorKey.self] = newValue }
}
}
extension View {
func primaryColor(_ primary: Color) -> some View {
environment(\.primaryColor, primary)
}
}
struct MyView: View {
#Environment(\.primaryColor) var primaryColor : Color
var body: some View {
VStack {
Text("label")
.foregroundColor(primaryColor)
}
}
}
struct ParentView: View {
var body: some View {
MyView()
.primaryColor(.red)
}
}