Updating CoreData adds a lot of nil values - ios

Question

I am trying to implement custom class to handle core data operations. It works great when creating new values. However when I want to update values I get nil entries in core data. Here is my code so far
/**
Update all records in given entity that matches input records
- parameters:
- entityName: name of entity to fetch
- updateBasedOnKey: name of key which will be used to identify entries that are going to be udpated
- values: NSMutableArray of all elements that are going to be updated
- important: if object with given updateBasedOnKey doesnt exist it will be created
- returns: nothing
*/
func updateRecord(entity: String, updateBasedOnKey: String, values: NSMutableArray){
let entityDescription = NSEntityDescription.entityForName(
entity, inManagedObjectContext: self.managedObjectContext)
let results = getRecords(entity)
for(elements) in values{
var newEntry = NSManagedObject(entity: entityDescription!, insertIntoManagedObjectContext: self.managedObjectContext)
//Determine whether to add new result or update existing
if(results.count > 0){
for result in results{
let entry = result as! NSManagedObject
if let keyValueToCompare = entry.valueForKey(updateBasedOnKey){
if (keyValueToCompare.isEqual(elements.valueForKey(updateBasedOnKey)) ){
//asign newEntry to result if found in entries
newEntry = entry
}
}
}
}
//update entry with new values
for(key, value) in elements as! NSMutableDictionary{
newEntry.setValue(value, forKey: key as! String)
}
//Try to save resulting entry
do {
try newEntry.managedObjectContext?.save()
} catch {
print(error)
}
}
}
/**
Fetch all records of given Entity in Core Data Model
- parameters:
- entityName: name of entity to fetch
- returns: NSArray of all records in given entity
*/
func getRecords(entity:String) -> NSArray{
let entityDescription = NSEntityDescription.entityForName(entity, inManagedObjectContext: self.managedObjectContext)
let fetchRequest = NSFetchRequest()
fetchRequest.entity = entityDescription
var result = NSArray()
do {
result = try self.managedObjectContext.executeFetchRequest(fetchRequest)
} catch {
let fetchError = error as NSError
print(fetchError)
}
return result
}
I think that problem is somewhere in asigning newEntry a NSManagedObject.
Any ideas how to fix this and get rid of nils?
Thanks in advance
EDIT:
this is actual working code created by implementing Wain suggestion
func updateRecord(entity: String, updateBasedOnKey: String, values: NSMutableArray){
let entityDescription = NSEntityDescription.entityForName(
entity, inManagedObjectContext: self.managedObjectContext)
let results = getRecords(entity)
for(elements) in values{
//set to true if value was already found and updated
var newEntry : NSManagedObject?
//Determine whether to add new result or update existing
if(results.count > 0){
for result in results{
let entry = result as! NSManagedObject
if let keyValueToCompare = entry.valueForKey(updateBasedOnKey){
if (keyValueToCompare.isEqual(elements.valueForKey(updateBasedOnKey)) ){
//asign newEntry to result if found in entries
newEntry = entry
}
}
}
}
if newEntry == nil {
newEntry = NSManagedObject(entity: entityDescription!, insertIntoManagedObjectContext: self.managedObjectContext)
}
for(key, value) in elements as! NSMutableDictionary{
newEntry!.setValue(value, forKey: key as! String)
}
}
}

Answer 1

You're right, the problem is that you're creating and inserting a new object each time. Instead you should be passing the object to update or running a fetch request to find it, then updating it.
It looks like your intention is to fetch, and the new entry should just be a reference, not initialised. So:
var newEntry : NSManagedObject?