CODEWITHSUNDEEP
ioscore-dataswiftui
Muz
Muz

Reputation: 759

How to update other CoreData when onDelete occurs in a ForEach?

There two entities Parent and Child, which is one to many relationship. One Parent and many Child.

I use EditMode to delete Child data like:

@ObservedObject private var db = CoreDataDB<Child>(predicate: "parent")

var body: some View {

    VStack {
        Form {

            Section(header: Text("Title")) {
                ForEach(db.loadDB(relatedTo: parent)) { child in

                    if self.editMode == .active {
                        ChildListCell(name: child.name, order: child.order)
                    } else {
                        ...
                    }
                }
                .onDelete(perform: self.db.deleting)   <--- How to update CoreData when delete occurs in this line
            }
        }
    }
}

The deleting method is defined in another Class like:

public func deleting(at indexset: IndexSet) {

    CoreData.executeBlockAndCommit {

        for index in indexset {
            CoreData.stack.context.delete(self.fetchedObjects[index])
        }
    }
}

And I also want to update other Attribute of Parent and Child Entities when onDelete occurs. How to make it?

Thanks for any help.

Upvotes: 1

Views: 45

Answers (1)

Asperi
Asperi

Reputation: 257663

Here is possible approach

Section(header: Text("Title")) {
    ForEach(db.loadDB(relatedTo: parent)) { child in

        if self.editMode == .active {
            ChildListCell(name: child.name, order: child.order)
        } else {
            ...
        }
    }
    .onDelete { indices in 
      // make other update here ...

      self.db.deleting(at: indices)

      // ... or here
    }
}

Upvotes: 1

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