Hello,
I've created multiple Entity in CoreData, that has a relationship to one another. However, I'm unable to create @discardableResult to use in SwiftUI preview.
/// Entity data for use with canvas previews.
static var preview: Entity1 {
let entities1 = Entity1.makePreviews(count: 1)
return entities1[0]
}
@discardableResult
static func makePreviews(count: Int) -> [Entity1] {
var contents = [Entity1]()
let viewContext = PersistenceController.preview.container.viewContext
let persistenceController = PersistenceController.shared
for index in 0..<count {
let entities1 = Entity1(context: viewContext)
entities1.id = UUID()
entities1.title = "Amazing day!"
let photo = Photo(context: viewContext)
let imageData = UIImage(named: "Golden Temple")?.jpegData(compressionQuality: 1) ?? Data()
photo.linkedToJournal = journal
let thumbnail = Thumbnail(context: viewContext)
let thumbnailData = persistenceController.thumbnail(with: imageData)?.jpegData(compressionQuality: 1)
thumbnail.data = thumbnailData
thumbnail.photo = photo
let photoDataObject = PhotoData(context: viewContext)
photoDataObject.data = imageData
photoDataObject.photo = photo
contents.append(entities1)
}
return contents
}
You may also try to use the sample code from https://developer.apple.com/documentation/coredata/sharing_core_data_objects_between_icloud_users to build a SwiftUI Preview.
Appreciate if you could suggest how to build a SwiftUI preview as it saves a lot of development effort and time. Thank you very much!
Found a solution! Can refer to sample code here for solution: https://developer.apple.com/documentation/coredata/adopting_swiftdata_for_a_core_data_app to use multiple entity and to preview your UI in XCode Canvas.