swiftdata relationship xcode15b3 ios17

Question

mandriao84 OP

Created Jul ’23

Replies 1

Boosts 1

Views 1.1k

Participants 2

I can't find a way to make this relationship, Anyone to tell me what am i doing wrong please ?

import SwiftUI
import SwiftData

@Model class Model1 {
    @Attribute(.unique) var id:String
    var date:Date
    @Relationship(.cascade) var model2:[Model2]
    init() {
        self.id = UUID().uuidString
        self.date = Date()
        self.model2 = []
    }
}

@Model class Model2 {
    @Attribute(.unique) var id:String
    var date:Date
    @Relationship(inverse: \Model1.model2) var model1:Model1
    init(
        model1:Model1
    ) {
        self.id = UUID().uuidString
        self.date = Date()
        self.model1 = model1
    }
}

struct view1:View {
    @Environment(\.modelContext) private var db
    var body: some View {
        Text("TapMe")
            .onTapGesture {
                let m1 = Model1()
                db.insert(m1)
                let m2 = Model2(model1: m1)
                db.insert(m2)
            }
    }
}

Error :

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'm1' between objects in different contexts (source = <NSManagedObject: 0x280b253b0> (entity: Model2; id: 0x282896ca0 <x-coredata:///Model2/tCB971C15-AFE3-46A2-A1FB-E688E0EF2ABF207>; data: {
    date = "2023-07-10 20:22:56 +0000";
    id = "625B994D-24BB-4935-A438-8AA6522C0FE1";
    m1 = nil;
}) , destination = <NSManagedObject: 0x280b250e0> (entity: Model1; id: 0x2828eaa40 <x-coredata:///Model1/tCB971C15-AFE3-46A2-A1FB-E688E0EF2ABF206>; data: {
    date = "2023-07-10 20:22:56 +0000";
    id = "BA3E6CF3-67EC-41CA-A150-E66E0D7226B2";
    m2 =     (
    );
}))'

Answered by milutz in 758638022

Currently it only seems to work, if the model1 relationship in Model2 is optional and only set after the insert:

[...]
let m2 = Model2()
db.insert(m2)
m2.model1 = m1
[...]
db.save()

See also here and here. I filed FB12363892 for that back in beta 1, but no reaction so far.

Boost

Answer 1

milutz OP

Jul ’23

Accepted Answer

Currently it only seems to work, if the model1 relationship in Model2 is optional and only set after the insert:

[...]
let m2 = Model2()
db.insert(m2)
m2.model1 = m1
[...]
db.save()

See also here and here. I filed FB12363892 for that back in beta 1, but no reaction so far.

1