NSManagedObject helpful additions

NSManagedObject+Additions.h

#import <CoreData/CoreData.h>

@interface NSManagedObject (Additions)

#pragma mark - Life cycle management

+ (id)createInContext:(NSManagedObjectContext *)context;
- (void)deleteInContext:(NSManagedObjectContext *)context;


#pragma mark - Fetching

+ (NSArray *)fetchInContext:(NSManagedObjectContext *)context;

+ (NSArray *)fetchWithFetchRequest:(NSFetchRequest *)fetchRequest
                         inContext:(NSManagedObjectContext *)context;

+ (NSArray *)fetchWithPredicate:(NSPredicate *)predicate
                      inContext:(NSManagedObjectContext *)context;

+ (NSArray *)fetchWithSortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors
                            inContext:(NSManagedObjectContext *)context;

+ (NSArray *)fetchWithPredicate:(NSPredicate *)predicate
                sortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors
                      inContext:(NSManagedObjectContext *)context;


#pragma mark - Counting

+ (NSInteger)countInContext:(NSManagedObjectContext *)context;

+ (NSInteger)countWithPredicate:(NSPredicate *)predicate
                      inContext:(NSManagedObjectContext *)context;

+ (NSInteger)countForFetchRequest:(NSFetchRequest *)fetchRequest
                        inContext:(NSManagedObjectContext *)context;

#pragma mark - Existing

+ (BOOL)existInContext:(NSManagedObjectContext *)context;

+ (BOOL)existWithPredicate:(NSPredicate *)predicate
                 inContext:(NSManagedObjectContext *)context;

#pragma mark - Fetch request management

+ (NSFetchRequest *)fetchRequestForCurrentEntity;

+ (NSFetchRequest *)fetchRequestWithPredicate:(NSPredicate *)predicate;

+ (NSFetchRequest *)fetchRequestWithSortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors;

+ (NSFetchRequest *)fetchRequestWithPredicate:(NSPredicate *)predicate
                              sortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors;

@end

NSManagedObject+Additions.m

#import "NSManagedObject+Additions.h"

@implementation NSManagedObject (Additions)

#pragma mark - Life cycle management

+ (id)createInContext:(NSManagedObjectContext *)context {
    return [NSEntityDescription insertNewObjectForEntityForName:NSStringFromClass(self)
                                         inManagedObjectContext:context];
}

- (void)deleteInContext:(NSManagedObjectContext *)context {
    [context deleteObject:self];
}


#pragma mark - Fetching

+ (NSArray *)fetchInContext:(NSManagedObjectContext *)context {
    NSFetchRequest *fetchRequest = [self fetchRequestForCurrentEntity];
    return [self fetchWithFetchRequest:fetchRequest inContext:context];
}

+ (NSArray *)fetchWithFetchRequest:(NSFetchRequest *)fetchRequest
                         inContext:(NSManagedObjectContext *)context {
    
    NSError *__autoreleasing error = nil;
    NSArray *objects = [context executeFetchRequest:fetchRequest
                                              error:&error];
    return objects;
}

+ (NSArray *)fetchWithPredicate:(NSPredicate *)predicate
                      inContext:(NSManagedObjectContext *)context {
    
    NSFetchRequest *fetchRequest = [self fetchRequestWithPredicate:predicate];
    return [self fetchWithFetchRequest:fetchRequest
                             inContext:context];
}

+ (NSArray *)fetchWithSortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors
                            inContext:(NSManagedObjectContext *)context {
    
    NSFetchRequest *fetchRequest = [self fetchRequestWithSortDescriptors:sortDescriptors];
    return [self fetchWithFetchRequest:fetchRequest
                             inContext:context];
}

+ (NSArray *)fetchWithPredicate:(NSPredicate *)predicate
                sortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors
                      inContext:(NSManagedObjectContext *)context {
    
    NSFetchRequest *fetchRequest = [self fetchRequestWithPredicate:predicate
                                                   sortDescriptors:sortDescriptors];
    return [self fetchWithFetchRequest:fetchRequest
                             inContext:context];
}


#pragma mark - Counting

+ (NSInteger)countInContext:(NSManagedObjectContext *)context {
    NSFetchRequest *fetchRequest = [self fetchRequestForCurrentEntity];
    return [self countForFetchRequest:fetchRequest
                            inContext:context];
}

+ (NSInteger)countWithPredicate:(NSPredicate *)predicate
                      inContext:(NSManagedObjectContext *)context {
    
    NSFetchRequest *fetchRequest = [self fetchRequestWithPredicate:predicate];
    return [self countForFetchRequest:fetchRequest
                            inContext:context];
}

+ (NSInteger)countForFetchRequest:(NSFetchRequest *)fetchRequest
                        inContext:(NSManagedObjectContext *)context {
    
    NSError *__autoreleasing error = nil;
    return [context countForFetchRequest:fetchRequest error:&error];
}


#pragma mark - Existing

+ (BOOL)existInContext:(NSManagedObjectContext *)context {
    return [self existWithPredicate:nil inContext:context];
}

+ (BOOL)existWithPredicate:(NSPredicate *)predicate
                 inContext:(NSManagedObjectContext *)context {
    NSFetchRequest *fetchRequest = [self fetchRequestForCurrentEntity];
    fetchRequest.predicate = predicate;
    fetchRequest.fetchLimit = 1;
    
    NSInteger count = [self countForFetchRequest:fetchRequest inContext:context];
    return (count > 0);
}

#pragma mark - Fetch request management

+ (NSFetchRequest *)fetchRequestForCurrentEntity {
    return [NSFetchRequest fetchRequestWithEntityName:NSStringFromClass(self)];
}

+ (NSFetchRequest *)fetchRequestWithPredicate:(NSPredicate *)predicate {
    return [self fetchRequestWithPredicate:predicate sortDescriptors:nil];
}

+ (NSFetchRequest *)fetchRequestWithSortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors {
    return [self fetchRequestWithPredicate:nil sortDescriptors:sortDescriptors];
}

+ (NSFetchRequest *)fetchRequestWithPredicate:(NSPredicate *)predicate
                              sortDescriptors:(NSArray <NSSortDescriptor*> *)sortDescriptors {
    NSFetchRequest *fetchRequest = [self fetchRequestForCurrentEntity];
    fetchRequest.predicate = predicate;
    fetchRequest.sortDescriptors = sortDescriptors;
    
    return fetchRequest;
}

@end