Realm Wrapper Example

README.md

1. "Realm builder" block is injected to a wrapper class
2. GCD queue is injected to a wrapper class
3. Realm is not accessed directly outside a wrapper class. It's only constructed there.
4. Each query returns unmanaged POD objects.

POD == "Plain Old Data"

HPLabRepositoryRealm.h

@interface HPLabRepositoryRealm : NSObject <HPLabModelRepository>

- (instancetype)init NS_UNAVAILABLE;
+ (instancetype) new NS_UNAVAILABLE;

- (instancetype)initWithRealm:(RLMRealmBuilderBlock)realmBuilder
               operationQueue:(dispatch_queue_t)queue
    NS_REQUIRES_SUPER
    NS_DESIGNATED_INITIALIZER
    __attribute__((nonnull));

@end
  
  

HPLabRepositoryRealm.m

#import "HPLabRepositoryRealm.h"

// entity
#import "HPLabRecordRealm.h"



@interface HPLabRepositoryRealm ()

@property (nonatomic) RLMRealmBuilderBlock realmBuilder;
@property (nonatomic) dispatch_queue_t queue;

@end

  
@implementation HPLabRepositoryRealm
  
- (void)loadLabRecordsAsync:(OnLabResultsListLoadedBlock)callback
{
    NSParameterAssert(nil != callback);

    __weak HPLabRepositoryRealm* weakSelf = self;
    RLMRealmBuilderBlock realmBuilder = self.realmBuilder;

    GCDActionBlock task = ^void() {

        HPLabRepositoryRealm* strongSelf = weakSelf;

        RLMRealm* realm = realmBuilder();

        NSArray<HPLabRecordPOD*>* unmanagedLabs = [strongSelf loadLabRecordsListInRealm:realm];
        callback(unmanagedLabs, nil);
    };

    dispatch_async(self.queue, task);
}


- (NSArray<HPLabRecordPOD*>*)loadLabRecordsListInRealm:(RLMRealm*)realm
{
    RLMResults* sortedDataset = [self sortedDatasetForLabRecordsListInRealm:realm];

    NSArray* result = [self getUnmanagedRecordListForDataset:sortedDataset];
    return result;
}
  

- (NSArray<HPLabRecordPOD*>*)getUnmanagedRecordListForDataset:(RLMResults*)dataset
{
    NSMutableArray* result = [NSMutableArray new];
    for (HPLabRecordRealm* managedLabRecord in dataset)
    {
        HPLabRecordPOD* unmanagedLabrecord = [[HPLabRecordPOD alloc] initWithLabRecord:managedLabRecord];
        [result addObject:unmanagedLabrecord];
    }

    NSArray* immutableResult = [NSArray arrayWithArray:result];
    return immutableResult;
}

@end