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POpopulating core data model through JSON with multiple Entities
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copied!<p>Having an issue populating a core data model with two entities through a JSON file,</p> <p>I managed to populate the first entity with no issues, but once i tried populating the second entity, received an error stating the data parameter is nil,</p> <p>Ive checked that I've used the correct json file name (Weights.json).</p> <p>Below is the code:</p> <pre><code> // Create the managed object context NSManagedObjectContext *context = managedObjectContext(); // Save the managed object context NSError *error = nil; if (![context save:&error]) { NSLog(@"Error while saving %@", ([error localizedDescription] != nil) ? [error localizedDescription] : @"Unknown Error"); exit(1); } NSError* err = nil; NSString* dataPath = [[NSBundle mainBundle] pathForResource:@"Exercises" ofType:@"json"]; NSArray* exercisesFromJSON = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath] options:kNilOptions error:&err]; //NSLog(@"Imported exercisesFromJSON: %@", exercisesFromJSON); [exercisesFromJSON enumerateObjectsUsingBlock:^(NSDictionary *exerciseDictionary, NSUInteger idx, BOOL *stop) { Exercise *exercise = [NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:context]; NSDictionary *attributes = [[exercise entity] attributesByName]; for (NSString *attribute in [attributes allKeys]) { id value = [exerciseDictionary objectForKey:attribute]; if (value == nil) { continue; } [exercise setValue:value forKey:attribute]; } NSError *error; if (![context save:&error]) { NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]); } }]; NSString* secondDataPath = [[NSBundle mainBundle] pathForResource:@"Weights" ofType:@"json"]; NSArray* weightsFromJSON = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:secondDataPath] options:kNilOptions error:&err]; ///***Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'****////// NSLog(@"Imported weightsFromJSON: %@", weightsFromJSON); [weightsFromJSON enumerateObjectsUsingBlock:^(NSDictionary *weightDictionary, NSUInteger idx, BOOL *stop) { Weight *weight = [NSEntityDescription insertNewObjectForEntityForName:@"Weight" inManagedObjectContext:context]; NSDictionary *attributes = [[weight entity] attributesByName]; for (NSString *attribute in [attributes allKeys]) { id value = [weightDictionary objectForKey:attribute]; if (value == nil) { continue; } [weight setValue:value forKey:attribute]; } NSError *error; if (![context save:&error]) { NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]); } }]; </code></pre> <p>thank you in advance for any help.</p>

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