CODEWITHSUNDEEP
swiftcore-dataswiftui
Ammar Ahmad
Ammar Ahmad

Reputation: 884

SwiftUI Core Data NSManagedObjectContext "unrecognized selector sent to instance" Error

In view model I try to call two functions one of them create new list "addNewList" and in side this function I create a new sublist "addMainSublist" as shown in the code bellow, the "addNewList" function work perfectly. Also, when I try to call the "addMainSublist" inside "addNewList" the error in the photo shown inside "PersistenceController" file when I try to save the new sublists in CoreData, I call the "addNewList" inside SwiftUI view and take "moc" parameter from "@Environment(.managedObjectContext) private var managedObjectContext" property in the SwiftUI view.

Note: as you see in the code bellow I use the same "managedObjectContext" to save both new list and new sublist, when I erase all content in the simulator and try to create new list the error did not show but in the second try the error shown again.

    func addNewList(moc: NSManagedObjectContext, mainLists: FetchedResults<ListOfTasks>, favoriteLists: FetchedResults<ListOfTasks>) {
    
    let newList = ListOfTasks(context: moc)
    newList.id = UUID()
    newList.addedDate = addedDate
    newList.title = title
    newList.icon = icon
    newList.color = Color.set(stringfor: color)
    newList.origin_Group = origin_Group
    if origin_Group == nil {
        newList.state = ListState.list.rawValue
        newList.index = Int16(mainLists.count)
        newList.isFavorite = isFavorite
        newList.favoriteIndex = Int16(isFavorite ? favoriteLists.count : 0)
    }else{
        if let wrappedGroup = origin_Group {
            newList.state = ListState.sublist.rawValue
            newList.index = Int16(wrappedGroup.listsArray.count-1)
            newList.isFavorite = false
            newList.favoriteIndex = 0
        }
    }
    newList.isLocked = isLocked
    newList.isArchived = isArchived
    
    PersistenceController.shared.save()
    
    addMainSublist(to: newList, moc: moc)

}


func addMainSublist(to newList: ListOfTasks, moc: NSManagedObjectContext) {
    
    let mainSublist = Sublist(context: moc)
    mainSublist.origin_List = newList
    mainSublist.id = UUID()
    mainSublist.addedDate = Date()
    mainSublist.index = 0
    mainSublist.title = "\(title)_MainSublist"
    mainSublist.isExpanded = false
    mainSublist.isArchived = false
            
    PersistenceController.shared.save()
}

Error Photo

enter image description here

Upvotes: 0

Views: 964

Answers (2)

Wallace Wittkoff
Wallace Wittkoff

Reputation: 21

Not the issue specifically here but in case on your search you come across this same error, check if you have your "one to many" or "one to one" relationship set correctly. That was my case where I forgot to change it to "one to many" when I set up the relationship between two entities. That solved my error.

Upvotes: 2

Ammar Ahmad
Ammar Ahmad

Reputation: 884

The answer by Joakim Danielson who gives me the note about "compare", the problem is using sort description "list.title" to fetch all sublists in the SwiftUI view for debugging, and when I change that the error is gone, thanks for "Joakim Danielson" for his valuable note.

Upvotes: 0

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