How to save NSArray data in coredata? - ios

Question

I want to save my data in coredata from NSArray. How can I achieve this ?
NSArray *fetchdata = [Lockbox arrayForKey:#"fetch"];
Here, I am getting data in below form:
How can I save this data in NSManageobject?
Here is my try:
NSFetchRequest *fetchrequestforside=[NSFetchRequest fetchRequestWithEntityName:#"demo"];
NSManagedObjectContext *context = [self managedObjectContext];
NSManagedObject *newDevice1 = [NSEntityDescription
insertNewObjectForEntityForName:#"demo"
inManagedObjectContext:context];
NSArray *fetchdata = [Lockbox arrayForKey:#"fetch"]; //
for (int i =0;i<[fetchdata count];i++){
NSString *Name = [[fetchdata objectAtIndex:i] objectForKey:#"name"];
NSString *Websitename = [[fetchdata objectAtIndex:i] objectForKey:#"websitename"];
NSString *Feedlink = [[fetchdata objectAtIndex:i] objectForKey:#"feedurl"];
NSLog(#"value:%#,%#,%#",Name,Websitename,Feedlink);
[newDevice1 setValue:Name forKey:#"name"];
[newDevice1 setValue:Websitename forKey:#"websitename"];
[newDevice1 setValue:Feedlink forKey:#"feedurl"];
NSLog(#"value:%#,%#,%#",Name,Websitename,Feedlink);
// Save the context.
NSError *error = nil;
if (![context save:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
But with this technique I am getting an error. How can I resolve this problem?
EDIT:-
I am getting this error:
*** Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '-[__NSCFString objectForKey:]:
unrecognized selector sent to instance 0x7ff262520660'

Answer 1

Your code treats the contents of the fetchdata array as instances of NSDictionary, but, LockBox only appears to support string contents:
-(NSArray *)arrayForKey:(NSString *)key
{
NSArray *array = nil;
NSString *components = [self objectForKey:key];
if (components)
array = [NSArray arrayWithArray:[components componentsSeparatedByString:kDelimiter]];
return array;
}
So, you need to deal with the conversion. You're probably part dealing with it already to store the original array...
But, that's why you get the error, the code expects a dictionary but actually gets a string

Answer 2

Do you have an object that looks like this?
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#interface demo : NSManagedObject
#property (nonatomic, retain) NSString * name;
#property (nonatomic, retain) NSString * websitename;
#property (nonatomic, retain) NSString * feedurl;
#end
After creating an object like this (using insertNewObjectForEntityForName) try to fetch it like that:
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:entityName inManagedObjectContext:self.managedObjectContext];
[request setEntity:entity];
NSArray *results = [self.managedObjectContext executeFetchRequest:request error:&error];
Btw, I would recommended you to stick to the naming conventions and call it Demo.
Cheers

Answer 3

I advice you to use the awesome library MagicalRecord
it save much time and very easy
here its tutorial
MagicalRecord Tutorial