NSUserDefaults access via properties.
Objective-C Ruby
Latest commit d3b90c1 Jan 19, 2016 @kevinrenskers kevinrenskers Add support for tvOS


GVUserDefaults - NSUserDefaults access via properties

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Tired of writing all that code to get and set defaults in NSUserDefaults? Want to have code completion and compiler checks by using properties instead?


Create a category on GVUserDefaults, add some properties in the .h file and make them @dynamic in the .m file.

// .h
@interface GVUserDefaults (Properties)
@property (nonatomic, weak) NSString *userName;
@property (nonatomic, weak) NSNumber *userId;
@property (nonatomic) NSInteger integerValue;
@property (nonatomic) BOOL boolValue;
@property (nonatomic) float floatValue;

// .m
@implementation GVUserDefaults (Properties)
@dynamic userName;
@dynamic userId;
@dynamic integerValue;
@dynamic boolValue;
@dynamic floatValue;

Now, instead of using [[NSUserDefaults standardUserDefaults] objectForKey:@"userName"], you can simply use [GVUserDefaults standardUserDefaults].userName.

You can even save defaults by setting the property:

[GVUserDefaults standardUserDefaults].userName = @"myusername";

Key prefix

The keys in NSUserDefaults are the same name as your properties. If you'd like to prefix or alter them, add a transformKey: method to your category. For example, to turn "userName" into "NSUserDefaultUserName":

- (NSString *)transformKey:(NSString *)key {
    key = [key stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[key substringToIndex:1] uppercaseString]];
    return [NSString stringWithFormat:@"NSUserDefault%@", key];

Registering defaults

Registering defaults can be done as usual, on NSUserDefaults directly (use the same prefix, if any!).

NSDictionary *defaults = @{
    @"NSUserDefaultUserName": @"default",
    @"NSUserDefaultUserId": @1,
    @"NSUserDefaultBoolValue": @YES

[[NSUserDefaults standardUserDefaults] registerDefaults:defaults];

However, it's a lot easier to create a setupDefaults method on the category, which takes care of the transformed keys automatically:

- (NSDictionary *)setupDefaults {
    return @{
        @"userName": @"default",
        @"userId": @1,
        @"boolValue": @YES

NSUserDefaults initWithSuitName support

Simply create a methods called suitName in your category and return the suitName you wish to use:

- (NSString *)suitName {
    return @"com.example.mySuitName";


Performance is nearly identical to using NSUserDefaults directly. We're talking about a difference of 0.05 milliseconds or less.


Install via CocoaPods (pod 'GVUserDefaults') or drag the code in the GVUserDefaults subfolder to your project.

Issues and questions

Have a bug? Please create an issue on GitHub!


GVUserDefaults is an open source project and your contribution is very much appreciated.

  1. Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug.
  2. Fork the repository on Github and make your changes on the develop branch (or branch off of it). Please retain the code style that is used in the project.
  3. Write tests, make sure everything passes.
  4. Send a pull request.


GVUserDefaults is available under the MIT license. See the LICENSE file for more info.


A huge thank you goes to ADVUserDefaults for its method of creating accessors for primitive types.