How to call SwiftUI NavigationLink conditionally?

user_3278728 0
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I'm thinking how to conditionally permit to start NavigationLink when user has tapped it. In UIKit it is just obvious but in SwiftUI this seems to me a huge problem. I know that I could declare NavigationLink somewhere in my view i.e.

@State private var isFired = false

/* (...) */

NavigationLink(destination: AnotherView(), isActive: $isFired) { EmptyView() }

and call it like this

Button(action: {
    if /* check condition */ {
        self.isFired = true
    } else {
        print("condition is not fulfilled")
    }
}) {
    Image("my-image")
}

but... the problem is: my navigation links are created dynamically in a loop and are wrapping images in ScrollView, i.e.

ScrollView(.vertical) {
    ForEach(photos, id: \.self) { element in
        NavigationLink(destination: ImagePreviewView(photo: element)) {
            Image(uiImage: element.image)
        }
    }
}

How to conditionally allow to start the navigation link in the code above? For example: user tapps an image -> a password request is presented -> if the password is correct the navigation link fires, if not the app does something else (presents alert etc. doesn't matter)

swiftui-navigationlink swiftui swift
1 Answers

Anyway it should be a button... something like

ScrollView(.vertical) {
    ForEach(photos, id: \.self) { element in
        Button(action: {
           // here call a function with callback provided if password
           // verification passed
           self.checkPassword { verified in
             if verified {
                self.photo = element  // store tapped element
                self.isFired = true   // << this might be called async
             }
           }
        }) {
            Image(uiImage: element.image)
        }
    }
}
.background(
   // activate link for tapped photo
   NavigationLink(destination: ImagePreviewView(photo: self.photo), 
      isActive: $isFired) { EmptyView() }
)
user_122990300
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