NSManagedObjectContext+MagicalSaves.m

//
//  NSManagedObjectContext+MagicalSaves.m
//  Magical Record
//
//  Created by Saul Mora on 3/9/12.
//  Copyright (c) 2012 Magical Panda Software LLC. All rights reserved.
//

#import "NSManagedObjectContext+MagicalSaves.h"
#import "MagicalRecord+ErrorHandling.h"
#import "NSManagedObjectContext+MagicalRecord.h"
#import "MagicalRecord.h"

@interface NSManagedObjectContext (InternalMagicalSaves)

- (void) MR_saveWithErrorCallback:(void(^)(NSError *))errorCallback;

@end


@implementation NSManagedObjectContext (MagicalSaves)

- (void) MR_saveWithErrorCallback:(void(^)(NSError *))errorCallback;
{
    if (![self hasChanges])
    {
        MRLog(@"NO CHANGES IN CONTEXT %@ - NOT SAVING", [self MR_description]);
        return;
    }
    
    MRLog(@"-> Saving %@", [self MR_description]);
    
    __block NSError *error = nil;
	__block BOOL saved = NO;
	@try
	{
        [self performBlockAndWait:^{
            saved = [self save:&error];
        }];
	}
	@catch (NSException *exception)
	{
		MRLog(@"Unable to perform save: %@", (id)[exception userInfo] ?: (id)[exception reason]);
	}
	@finally
    {
        if (!saved)
        {
            if (errorCallback)
            {
                errorCallback(error);
            }
            else
            {
                [MagicalRecord handleErrors:error];
            }
        }
    }
}

- (void) MR_saveNestedContexts;
{
    [self MR_saveNestedContextsErrorHandler:nil];
}

- (void) MR_saveNestedContextsErrorHandler:(void (^)(NSError *))errorCallback;
{
    [self MR_saveNestedContextsErrorHandler:nil completion:nil];
}

- (void) MR_saveNestedContextsErrorHandler:(void (^)(NSError *))errorCallback completion:(void (^)(void))completion;
{
    [self performBlock:^{
        [self MR_saveWithErrorCallback:errorCallback];
        if ([self parentContext]) {
            [[self parentContext] performBlock:^{
                [[self parentContext] MR_saveNestedContextsErrorHandler:errorCallback completion:completion];
            }];
        } else {
            if (completion) {
                dispatch_async(dispatch_get_main_queue(), ^{
                    completion();
                });
            }
        }
    }];
}

- (void) MR_save;
{
    [self MR_saveWithErrorCallback:nil];
}

- (void) MR_saveInBackgroundCompletion:(void (^)(void))completion;
{
    [self MR_saveInBackgroundErrorHandler:nil completion:completion];
}

- (void) MR_saveInBackgroundErrorHandler:(void (^)(NSError *))errorCallback;
{
    [self MR_saveInBackgroundErrorHandler:errorCallback completion:nil];
}

- (void) MR_saveInBackgroundErrorHandler:(void (^)(NSError *))errorCallback completion:(void (^)(void))completion;
{
    [self performBlock:^{
        // Save the context
        [self MR_saveWithErrorCallback:errorCallback];
        
        // If we're the default context, save to disk too (the user expects it to persist)
        if (self == [[self class] MR_defaultContext])
        {
            [[[self class] MR_rootSavingContext] MR_saveInBackgroundErrorHandler:errorCallback completion:completion];
        }
        else
        {
            // If we are not the default context (And therefore need to save the root context, do the completion action if one was specified
            if (completion)
            {
                dispatch_async(dispatch_get_main_queue(), completion);
            }
        }
    }];
}
@end