Unable to show image form Core data on offline Mode In swift UI - swift

Question

I am using AsyncImage to download the image and display it into view. I have created the respective properties into core data including image type is string to save the data locally . I am trying to load the into offline mode , it was able to show the rest of the properties without Image and it showing blank ..
Here is the code for Core Data manager .
class CoreDataManager {
let persistentContainer: NSPersistentContainer
static let shared: CoreDataManager = CoreDataManager()
private init() {
persistentContainer = NSPersistentContainer(name: "ReditModel")
persistentContainer.loadPersistentStores { description, error in
if let error = error {
// fatalError("Unable to initialize Core Data \(error)")
print("Unable to save the data :\(error.localizedDescription)")
}
}
}
}
Here is the code for main ..
#main
struct CoreDataDemoApp: App {
#StateObject private var viewModel = RedditViewModel()
let persistentContainer = CoreDataManager.shared.persistentContainer
var body: some Scene {
WindowGroup {
ContentView().environment(\.managedObjectContext, persistentContainer.viewContext).environmentObject(viewModel)
}
}
}
Here is the view model..
#MainActor
class RedditViewModel: ObservableObject {
#Published private(set) var stories = [Story]()
private var redditService: RedditService
init(redditService: RedditService = RedditService()) {
self.redditService = redditService
}
// Swift 5.5
func fetchData(viewContext: NSManagedObjectContext) async {
let url = NetworkURLs.urlBase
do {
let response = try await redditService.getModel(from: url)
let stories = response.data.children.map { $0.data }
self.stories = stories
saveRecord(viewContext: viewContext)
} catch (let error) {
print(error)
}
}
public func saveRecord(viewContext: NSManagedObjectContext) {
do {
stories.forEach { story in
let redit = ReditEntity(context: viewContext)
redit.title = story.title
redit.numComments = Int64(story.numComments)
redit.score = Int64(story.score)
redit.urlImage = story.thumbnail
}
try viewContext.save()
} catch {
print(error.localizedDescription)
}
}
}
Here is the code for Row view .
struct RowView: View {
#EnvironmentObject var viewModel: RedditViewModel
let title: String
let comments: String
let score: String
let urlImage: String?
var body: some View {
VStack(alignment: .leading) {
HStack {
if let urlImage = urlImage, urlImage.contains("https"), let url = URL(string: urlImage) {
AsyncImage(url: url)
}
VStack(alignment: .leading) {
HeadTitleView(title: title)
Text("Comments: \(comments)")
Text("Score: \(score)")
Spacer()
}
}
}
}
}
Here is the content view ..
struct ContentView: View {
#EnvironmentObject private var viewModel: RedditViewModel
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(entity: ReditEntity.entity(), sortDescriptors: [])
private var dbStories: FetchedResults<ReditEntity>
var dbFatchReditRecord: NSFetchRequest<ReditEntity> = ReditEntity.fetchRequest()
var body: some View {
VStack {
Text("Reddit Service")
.font(.largeTitle)
List {
ForEach(dbStories) { story in
// custom cell
RowView(title: story.title ?? "", comments: "\(story.numComments)", score: "\(story.score)", urlImage: story.urlImage)
}
}
}
.onAppear {
if dbStories.isEmpty {
Task {
await viewModel.fetchData(viewContext: viewContext)
}
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
let persistedContainer = CoreDataManager.shared.persistentContainer
ContentView().environment(\.managedObjectContext, persistedContainer.viewContext) }
}
Here is the screenshot when I run the app on Offline model ..

Answer 1

Out of curiosity: How are you supposed to be able to load a https url while being offline?
-> urlImage.contains("https")
You should download the image and store it on your local file system. For example give your data model 2 attributes: offlineUrlString and onlineUrlString. Then as a fallback if the online url results in an empty image, then use the offline image. Once you are online again, update the offline image again.