Core Data - How to Insert an Array - iphone

Question

I'd like to know how to save several string objects, all stored in an array, using Core Data.
I understand how to store a single string, but is there any convenience method/can I store the array object itself rather than iterating over the array and storing each string item seperately?
NSManagedObject *alice = [NSEntityDescription insertNewObjectForEntityForName:#"Student" inManagedObjectContext:context];
[alice setValue:#"Alice" forKey:#"name"];
[alice setValue:#"Computer Science" forKey:#"major"];
Basically, can I have setValue be an array instead of Alice?
(As an unrelated question how can I cache data on the iphone, such as an image...)
Thanks for any help

Answer 1

Look at this post : insert NSDictionary into CoreData just replace the word NSDictionary by NSArray apart from that it's the same question.

Answer 2

I don't know if there are any prebuilt methods. You'd have to track keys in a separate container, for example, or define them as constants somewhere, such as in the following example:
static NSUInteger const kMyNameIdx = 0U;
static NSUInteger const kMyMajorIdx = 1U;
static NSString * const kMyNameKey = #"name";
static NSString * const kMyMajorKey = #"major";
/* this does no error checking on the mo or array */
/* being null. it would be better to return an */
/* NSError from this function and check its value */
/* to handle error cases */
- (void) updateManagedObject:(NSManagedObject *)mo withOrderedArray:(NSArray *)array
{
id obj;
NSUInteger objIdx = 0U;
/* this assumes that name and major objects in */
/* your array are in the same order as set by */
/* the constants */
for (obj in array) {
switch (objIdx) {
case kMyNameIdx:
[mo setValue:obj forKey:kMyNameKey];
break;
case kMyMajorIdx:
[mo setValue:obj forKey:kMyMajorKey];
break;
default:
break;
}
objIdx++;
}
}
To use it:
NSManagedObject *alice = [NSEntityDescription insertNewObjectForEntityForName:#"Student" inManagedObjectContext:context];
NSArray *myArray = /* ... */
[self updateManagedObject:alice withOrderedArray:myArray];
There are additional modifications you can make, such as making this a category method for NSManagedObject of entity type Student. Then you can call this function anywhere you use Student managed objects.

Answer 3

where ever you called this method with your array
-(void)viewDidLoad
{
[self insertLoginData:YOUR ARRAY NAME];
}
- (BOOL)insertLoginData:(NSMutableArray *)loginInfoArray
{
NSError *error=nil;
NSManagedObjectContext *context = [self managedObjectContext];
NSManagedObject *propertyInfo = [NSEntityDescription
insertNewObjectForEntityForName:#"UserLogin"
inManagedObjectContext:context];
for(int count=0;count<[loginInfoArray count];count++)
{
[propertyInfo setValue:[[loginInfoArray objectAtIndex:count]objectForKey:#"UserId"] forKey:#"userName"];
[propertyInfo setValue:[[loginInfoArray objectAtIndex:count]objectForKey:#"Password"] forKey:#"password"];
}
if (![__managedObjectContext save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
return NO;
}
else
{
return YES;
}
}
Fetch data ==========
-(NSMutableArray *)fetchLoginData
{
NSFetchRequest *fetchReq = [[NSFetchRequest alloc]init];
[fetchReq setEntity:[NSEntityDescription entityForName:#"UserLogin" inManagedObjectContext:self.managedObjectContext]];
NSMutableArray *resultArray = [[NSMutableArray alloc]initWithArray:[self.managedObjectContext executeFetchRequest:fetchReq error:nil]];
NSMutableArray *array=[[NSMutableArray alloc]init];
for(UserLogin *pnt in resultArray)
{
//[array addObject:pnt.userName];
[array addObject:pnt];
}
return array;
}