This is my entity object in my iOS app that uses CoreData.
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#import "Price.h"
@interface DataPrice : NSManagedObject
@property (nonatomic) NSInteger id;
@property (nonatomic, retain) NSNumber *ron95;
@property (nonatomic, retain) NSNumber *ron92;
@property (nonatomic, retain) NSNumber *dieselNormal;
@property (nonatomic, retain) NSNumber *dieselSpecial;
@property (nonatomic, retain) NSDate *postDate;
+ (instancetype)insertDataPriceWithPrice:(Price*)price
inManagedObjectContext:(NSManagedObjectContext *)managedObjectContext;
+ (instancetype)fetchDataPriceInManagedObjectContext:(NSManagedObjectContext *)managedObjectContext;
+ (Price*)fetchPriceInManagedObjectContext:(NSManagedObjectContext *)managedObjectContext;
@end
#import "DataPrice.h"
@implementation DataPrice
@dynamic id;
@dynamic ron95;
@dynamic ron92;
@dynamic dieselNormal;
@dynamic dieselSpecial;
@dynamic postDate;
+ (instancetype)insertDataPriceWithPrice:(Price*)price
inManagedObjectContext:(NSManagedObjectContext *)managedObjectContext
{
DataPrice* dataPrice = [NSEntityDescription insertNewObjectForEntityForName:self.entityName
inManagedObjectContext:managedObjectContext];
dataPrice.id = price.id;
dataPrice.ron95 = price.ron95;
dataPrice.ron92 = price.ron92;
dataPrice.dieselNormal = price.dieselNormal;
dataPrice.dieselSpecial = price.dieselSpecial;
dataPrice.postDate = price.postDate;
return dataPrice;
}
+ (NSString*)entityName
{
return @"Price";
}
+ (instancetype)fetchDataPriceInManagedObjectContext:(NSManagedObjectContext *)managedObjectContext {
NSEntityDescription *entity = [NSEntityDescription entityForName:self.entityName inManagedObjectContext:managedObjectContext];
if (!entity) {
return NULL;
}
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"postDate" ascending:NO];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
request.entity = entity;
request.sortDescriptors = @[ sortDescriptor ];
request.fetchLimit = 1;
NSError *error;
NSArray *fetchResults = [managedObjectContext executeFetchRequest:request error:&error];
DataPrice *result = fetchResults.firstObject;
return result;
}
+ (Price*)fetchPriceInManagedObjectContext:(NSManagedObjectContext *)managedObjectContext {
DataPrice *dataPrice = [self fetchDataPriceInManagedObjectContext:managedObjectContext];
Price *price = [[Price alloc] init];
price.id = dataPrice.id;
price.ron92 = dataPrice.ron92;
price.ron95 = dataPrice.ron95;
price.dieselNormal = dataPrice.dieselNormal;
price.dieselSpecial = dataPrice.dieselSpecial;
price.postDate = dataPrice.postDate;
return price;
}
@end
I named the class DataPrice
but want the entity to be Price
.
Do I need an xcdatamodel
for my application and how do I define one?
A. Yes, you need a data model. You get it with File | New … | File and in the sheet iOS | Core Data | Data Model.
However it is easier to create a Core Data application from the very beginning.
B. Classes and entity (types) can have different names. You simply can assign a class with a different name to the entity type. (Ny default NSManagedObject
is assigned, what is a different name for all entity types not called NSManagedObject
. ;-)) But there is little reason to do so.