SwiftData delete isn't working, when I attempt to delete a model, my app crashes and I get the following error:
SwiftData/PersistentModel.swift:359: Fatal error: Cannot remove My_App.Model2 from relationship Relationship - name: model2, options: [], valueType: Model2, destination: Model2, inverseName: models3, inverseKeypath: Optional(\Model2.models3) on My_App.Model3 because an appropriate default value is not configured.
I get that it's saying I don't have a default value, but why do I need one? Isn't @Relationship .cascade automatically deleting the associated models?
And onto of that, why is the error occurring within the do block, shouldn't it be caught by the catch, and printed?
I have put together a sample project below.
import SwiftUI
import SwiftData
@main
struct MyApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.modelContainer(for: Model3.self)
}
}
}
@Model
class Model1 {
var name: String
@Relationship(deleteRule: .cascade, inverse: \Model2.model1) var models2: [Model2] = []
init(name: String) {
self.name = name
}
}
@Model
class Model2 {
var name: String
var model1: Model1
@Relationship(deleteRule: .cascade, inverse: \Model3.model2) var models3: [Model3] = []
init(name: String, model1: Model1) {
self.name = name
self.model1 = model1
}
}
@Model
class Model3 {
var name: String
var model2: Model2
init(name: String, model2: Model2) {
self.name = name
self.model2 = model2
}
}
struct ContentView: View {
@Query var models1: [Model1]
@Environment(\.modelContext) var modelContext
var body: some View {
NavigationStack {
List(models1) { model1 in
Text(model1.name)
.swipeActions {
Button("Delete", systemImage: "trash", role: .destructive) {
modelContext.delete(model1)
do {
try modelContext.save()
//SwiftData/PersistentModel.swift:359: Fatal error: Cannot remove My_App.Model2 from relationship Relationship - name: model2, options: [], valueType: Model2, destination: Model2, inverseName: models3, inverseKeypath: Optional(\Model2.models3) on My_App.Model3 because an appropriate default value is not configured.
} catch {
print(error.localizedDescription)
}
}
}
}
.toolbar {
Button("Insert", systemImage: "plus") {
modelContext.insert(Model3(name: "model3", model2: Model2(name: "model2", model1: Model1(name: "model1"))))
}
}
}
}
}
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
Swift Student Challenge
SwiftUI
SwiftData