In project 11 we built Bookworm, an app that lets users store ratings and descriptions for books they had read, and we also introduced a custom
RatingView UI component that showed star ratings from 1 to 5.
Again, most of the app does well with VoiceOver, but that rating control is a hard fail – it uses tap gestures to add functionality, so users won’t realize they are buttons, and it doesn’t even convey the fact that they are supposed to represent ratings. For example, if I tap one of the gray stars, VoiceOver reads out to me, “star, fill, image, possibly airplane, star” – it’s really not useful at all.
That in itself is a problem, but it’s extra problematic because our
RatingView is designed to be reusable – it’s the kind of thing you can take from this project and use in a dozen other projects, and that just means you end polluting many apps with poor accessibility.
We can fix this with three modifiers, each added below the current
tapGesture() modifier inside
RatingView. First, we need to add one that provides a meaningful label for each star, like this:
.accessibility(label: Text("\(number == 1 ? "1 star" : "\(number) stars")"))
Second, we can remove the
.isImage trait, because it really doesn’t matter that these are images:
And finally, we should tell the system that each star is actually a button, so users know it can be tapped. While we’re here, we can make VoiceOver do an even better job by adding a second trait,
.isSelected, if the star is already highlighted.
So, add this final modifier beneath the previous two:
.accessibility(addTraits: number > self.rating ? .isButton : [.isButton, .isSelected])
It only took three small changes, but this improved component is much better than what we had before.
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