I have the following SwiftUI view that fails to compile with the error "Generic parameter 'Content' could not be inferred" but if I comment out the line context.doSomething() then it compiles and runs fine. It also works if I remove the Context class and just pass a Binding<Bool> into the closure directly.
What should I be doing to make it work, and why is the context.doSomething() line stopping the compiler from inferring what the Content parameter is?
public struct BrokenView<Content: View>: View {
@ViewBuilder var content: (_ context: Context) -> Content
public class Context: ObservableObject {
@Published var context: Bool = false
func doSomething() {
context.toggle()
}
}
@State var context = Context()
public init(@ViewBuilder content: @escaping (_ context: Context) -> Content) {
self.content = content
}
public var body: some View {
VStack {
content(context)
.padding()
}
}
}
#Preview {
BrokenView { context in // Error here
Text("Hello")
Button(action: {
context.doSomething() // Comment out to fix
}) {
Text("Goodbye")
}
}
}
Context is not known outside BrokenView.
I moved it out to make it compile.
import SwiftUI
public class Context: ObservableObject {
@Published var context: Bool = false
func doSomething() {
context.toggle()
}
}
public struct BrokenView<Content: View>: View {
@ViewBuilder var content: (_ context: Context) -> Content
// public class Context: ObservableObject {
// @Published var context: Bool = false
//
// func doSomething() {
// context.toggle()
// }
// }
@State var context = Context()
public init(@ViewBuilder content: @escaping (_ context: Context) -> Content) {
self.content = content
}
public var body: some View {
VStack {
content(context)
.padding()
}
}
}
#Preview {
BrokenView { context in // Error here
Text("Hello")
Button(action: {
context.doSomething() // Comment out to fix
}) {
Text("Goodbye")
}
}
}
