Problem when saving data to Core Data

App Development
1

Hi guys, I’m working with Core Data to save Criterion objects, but when I create and save an object, my app sometimes just stops responding. I don’t know what is going wrong in my code.

This is the function which the view code runs to add a criterion:

func addCriterion(title: String, info: String?) {
    // Create a new criterion with the input title and description
    let newCriterion = GoalCriterion.createObject(title: title, info: info, in: dataModel.viewContext)
    
    // Add the criterion to the shown list of criteria
    withAnimation(.bouncy) {
        criteria.insert(newCriterion, at: 0)
    }
    
    // Add the criterion to the goal
    dataModel.editGoal(addCriteria: [newCriterion])
}

It uses createObject which is a static function in the class declaration of my Core Data GoalCriterion object generated by XCode:

static func createObject(title: String,
                         info: String? = nil,
                         imageData: Data? = nil,
                         icon: String? = nil,
                         in viewContext: NSManagedObjectContext) -> Self {
    let newObject = GoalCriterion.init(context: viewContext)
    newObject.title = title
    newObject.info = info
    newObject.imageData = imageData
    newObject.icon = icon
    
    return newObject
}

It then adds this object to the views array which the view uses to show all added criteria, and then it saves the object using my DataModel and its editGoal function which saves the object to Core Data by adding it to the Goal object. (This is just the general object saved to Core Data, this object holds an array of criterion thus an addToCriteria function is generated by XCode automatically when generating the Core Data classes. This function is used by the editGoal function to add a criterion.):

func editGoal(title: String? = nil,
              info: String? = nil,
              chosenWay: String? = nil,
              pathSummary: String? = nil,
              addCriteria: NSSet? = nil,
              addPracticalGoals: NSSet? = nil,
              addSubgoals: NSSet? = nil,
              removeCriteria: NSSet? = nil,
              removePracticalGoals: NSSet? = nil,
              removeSubgoals: NSSet? = nil) {
    guard goal != nil else {
        // Notify the user
        UIHelper.presentAlert(.essentialDataError)
        return
    }
    
    // Change properties
    if title != nil { goal!.title = title }
    if info != nil { goal!.info = info }
    if chosenWay != nil { goal!.chosenWay = chosenWay }
    if pathSummary != nil { goal!.pathSummary = pathSummary }
    
    // Add elements
    if addCriteria != nil {
        goal!.addToCriteria(addCriteria!)
    }
    if addPracticalGoals != nil { goal!.addToPracticalGoals(addPracticalGoals!) }
    if addSubgoals != nil { goal!.addToSubgoals(addSubgoals!) }
    
    // Remove elements
    if removeCriteria != nil { goal!.removeFromCriteria(removeCriteria!) }
    if removePracticalGoals != nil { goal!.removeFromPracticalGoals(removePracticalGoals!) }
    if removeSubgoals != nil { goal!.removeFromSubgoals(removeSubgoals!) }
    
    // Save
    persistenceController.saveViewContext()
    
    // Re-fetch the goal
    fetchGoal()
}

func fetchGoal(noDataCompletion: (() -> Void)? = nil, completion: (() -> Void)? = nil) {
    do {
        let fetchedGoals: [Goal] = try viewContext.fetch(Goal.fetchRequest())
        
        if !fetchedGoals.isEmpty {
            DispatchQueue.main.async {
                self.goal = fetchedGoals.first!
            }
        } else {
            noDataCompletion?()
        }
        
        completion?()
    } catch {
        // Notify the user
        UIHelper.presentAlert(.essentialDataError)
    }
}

Is there something wrong with this code or is there a better approach? Thanks for any help!