NSManagedObject+Convenients

Overview

Using CoreData is now being essential part of iOS application development. But due to its cumbersome syntax, CoreData programming wasn't pleasure thing. Typing all NSManagedObjectContext, NSEntityDescription things is one of a key reason of CoreData programming difficulties.

So, these bunch of Objective-C categories for NSManagedObject or NSManagedObjectContext are written. These categories support convenient methods to create/retrieve CoreData NSManagedObjects.

It supports

• Basic CRUD methods for NSManagedObject
• NSDate and NSArray persistency to CoreData
• Automatically detect CamelCase and under_score key of NSDictionary
• Timestamp methods for tracking the last updated time of resources

Motivating Example

It is typical thing to access API server to get some Resource and persist them to CoreData for caching purpose. The most common representation of a resource is JSON. And a JSON object is easily converted to NSDictionary using many existing JSON parsers.

Say, your server has resources named User and your iOS application wants to save in CoreData.

#import "User.h" //a CoreData model
#import "NSManagedObject+Convenients.h" //Simply you import it and taste goodies
    
NSURL *url = [NSURL URLWithString:@"https://api.awesome-service.com/users/42"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];

AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request
  success:^(NSURLRequest *request, NSHTTPURLResponse *response, NSDictionary *JSON) {
  NSError *err;
  
  //Using categories doesn't require additional setups
  User *user = [User insertWithDictionary:JSON error:&err];
  
  //you are good to go with `user`
  
} failure:nil];

More Details

See sample project's unit test file for more deatils

Credits

• It is good to go with your modification. But, just leave my copyright though.
• I inspired from this blog post which describes single line fetch category method for NSManagedObjectContext. In this project, I slightly changed it for my flavour.