How to apply modifier or view by condition

Question

@State var modifierEnabled : Bool

struct BlankModifier: ViewModifier {
    func body(content: Content) -> some View {
        content
    }
}

extension View {
    func TestModifierView() -> some View{
       return self.modifier(BlankModifier())
    }
}

How to apply TestModifierView only in case of modifierEnabled == true ?

Answer 1

@available(OSX 11.0, *)
public extension View {
    @ViewBuilder
    func `if`<Content: View>(_ condition: Bool, content: (Self) -> Content) -> some View {
        if condition {
            content(self)
        } else {
            self
        }
    }
}

@available(OSX 11.0, *)
public extension View {
    @ViewBuilder
    func `if`<TrueContent: View, FalseContent: View>(_ condition: Bool, ifTrue trueContent: (Self) -> TrueContent, else falseContent: (Self) -> FalseContent) -> some View {
        if condition {
            trueContent(self)
        } else {
            falseContent(self)
        }
    }
}

usage example ( one modifier ) :

Text("some Text")
   .if(modifierEnabled) { $0.foregroundColor(.Red) }

usage example2 (two modifier chains related to condition) :

Text("some Text")
   .if(modifierEnabled) { $0.foregroundColor(.red) } 
   else:                { $0.foregroundColor(.blue).background(Color.green) }

BUT!!!!!!!!!!!

Important thing that this modifier can be reason of some indentity issues. (later you will understand this)

So in some cases better to use standard if construction