How to get random Core Data element from ForEach in Widget

Question

I'm working on a widget in iOS 14 that will show images from Core Data as submitted by my users. Currently, I can show a single image, but it's not rotating through the Project images.. it's only showing a single image in the widget.

In my Widget.swift, the only way I can get an image to show is by using a ForEach. If I don't use the ForEach, I get the error Value of type 'FetchedResults<Project>' has no member 'image1'

Here's the (mostly) working code

struct WidgetEntryView : View {
    var entry: Provider.Entry
    @State var projectImage1: Data = .init(count: 0)
    @FetchRequest(entity: Project.entity(), sortDescriptors: []) var project: FetchedResults<Project>
    
    var body: some View {
    
            ForEach((project.prefix(1)), id: \.self) { (project: Project) in
                Image(uiImage: UIImage(data: project.image1 ?? self.projectImage1) ?? UIImage(imageLiteralResourceName: "icon"))
                    .resizable()
                    .aspectRatio(contentMode: .fill)
            }.environment(\.managedObjectContext, managedObjectContext)
    }
}

Again, if I use the below code, I get the no member error for some reason

struct WidgetEntryView : View {
    var entry: Provider.Entry
    @State var projectImage1: Data = .init(count: 0)
    @FetchRequest(entity: Project.entity(), sortDescriptors: []) var project: FetchedResults<Project>
    
    var body: some View {
        
       Image(uiImage: UIImage(data: project.image1 ?? self.projectImage1) ?? UIImage(imageLiteralResourceName: "icon"))
                    .resizable()
                    .aspectRatio(contentMode: .fill)
        }.environment(\.managedObjectContext, managedObjectContext)
    }
}

How can I have the ForEeach show a random project.image1 attribute? I've tried appending randomElement() and shuffle() but neither are accepted.

Here's the full Widget.swift: https://pastebin.com/aFMuZ0iz

CSmith · Accepted Answer · 2021-03-17T18:05:18.843

0

FetchedResults<Project> is a collection data type, so it won't have an image1 property like an element in the collection of type Project. You're using the prefix(1) method which is returning a sub-collection with one element...but it's still a collection.

Try something like this:

if let randomProject: Project = project.randomElement()
{
   Image(uiImage: UIImage(data: randomProject.image1 ?? self.projectImage1))
}
else
{
   Image(uiImage: UIImage(imageLiteralResourceName: "icon"))
}

project.randomElement() will return a random element from the collection if not empty, else nil.

edited Mar 17 '21 at 18:05

answered Mar 17 '21 at 17:38

CSmith

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Had to keep the Image(uiImage:) for data conversion, but this works beautifully, thank you @CSmith! – phiredrop Mar 17 '21 at 17:58
oops my bad on the Image() syntax, I edited the answer. Glad to help – CSmith Mar 17 '21 at 18:05

How to get random Core Data element from ForEach in Widget

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