SwiftyUserDefaults 2.0

SwiftyUserDefaults makes NSUserDefaults cleaner, nicer and easier to use in Swift. Its statically-typed API gives you extra safety and convenient compile-time checks for free.

Read Swifty APIs: NSUserDefaults and Statically-typed NSUserDefaults for more information about this project.

Define your keys

To get the most out of SwiftyUserDefaults, we recommend defining your user defaults keys ahead of time:

let colorKey = DefaultsKey<String>("color")

Just create a DefaultsKey object, put the value type in angled brackets and the key name in parentheses and you're good to go.

You can now use the global Defaults object:

Defaults[colorKey] = "red"
Defaults[colorKey] // => "red", typed as String

The compiler won't let you set a wrong value type, and fetching conveniently returns String — no need for manual casting or special accessors.

Take shortcuts

For extra convenience, define your keys by extending DefaultsKeys and adding static properties:

extension DefaultsKeys {
    static let username = DefaultsKey<String?>("username")
    static let launchCount = DefaultsKey<Int>("launchCount")
}

And use the shortcut dot syntax:

Defaults[.username] = "joe"
Defaults[.launchCount]

Just use it!

You can easily modify value types (strings, numbers, array) in place, without extra steps or magic operators, as if you were working with a plain old dictionary:

// Modify value types in place
Defaults[.launchCount]++
Defaults[.volume] += 0.1
Defaults[.strings] += "… can easily be extended!"

// Use and modify typed arrays
Defaults[.libraries].append("SwiftyUserDefaults")
Defaults[.libraries][0] += " 2.0"

// Easily work with custom serialized types
Defaults[.color] = NSColor.whiteColor()
Defaults[.color]?.whiteComponent // => 1.0

Supported types

SwiftyUserDefaults supports all of the standard NSUserDefaults types, like strings, numbers, booleans, arrays and dictionaries.

Here's a full table:

Optional variant	Non-optional variant	Default value
String?	String	""
Int?	Int	0
Double?	Double	0.0
Bool?	Bool	false
NSData?	NSData	NSData()
[AnyObject]?	[AnyObject]	[]
[String: AnyObject]?	[String: AnyObject]	[:]
NSDate?	n/a	n/a
NSURL?	n/a	n/a
AnyObject?	n/a	n/a
NSString?	NSString	""
NSArray?	NSArray	[]
NSDictionary?	NSDictionary	[:]

You can mark a type as optional to get nil if the key doesn't exist. Otherwise, you'll get a default value that makes sense for a given type.

Typed arrays

Additionally, typed arrays are available for these types:

Array type	Optional variant
[String]	[String]?
[Int]	[Int]?
[Double]	[Double]?
[Bool]	[Bool]?
[NSData]	[NSData]?
[NSDate]	[NSDate]?

Custom types

You can easily store custom NSCoding-compliant types by extending NSUserDefaults with this stub subscript:

extension NSUserDefaults {
    subscript(key: DefaultsKey<NSColor?>) -> NSColor? {
        get { return unarchive(key) }
        set { archive(key, newValue) }
    }
}

Just copy&paste this and change NSColor to your class name. If you want, you can also remove ? marks and coalesce nils: unarchive(key) ?? yourDefaultValue.

Here's an example use:

extension DefaultsKeys {
    static let color = DefaultsKey<NSColor?>("color")
}

Defaults[.color] // => nil
Defaults[.color] = NSColor.whiteColor()
Defaults[.color] // => w 1.0, a 1.0
Defaults[.color]?.whiteComponent // => 1.0

Existence

if !Defaults.hasKey(.hotkey) {
    Defaults.remove(.hotkeyOptions)
}

You can use the hasKey method to check for key's existence in the user defaults. remove() is an alias for removeObjectForKey(), that also works with DefaultsKeys shortcuts.

Legacy stringly-typed API

There's also a more traditional string-based API available. This will be deprecated and removed in future versions of this library — it's recommended you use the new static keys API.

Defaults["color"].string            // returns String?
Defaults["launchCount"].int         // returns Int?
Defaults["chimeVolume"].double      // returns Double?
Defaults["loggingEnabled"].bool     // returns Bool?
Defaults["lastPaths"].array         // returns NSArray?
Defaults["credentials"].dictionary  // returns NSDictionary?
Defaults["hotkey"].data             // returns NSData?
Defaults["firstLaunchAt"].date      // returns NSDate?
Defaults["anything"].object         // returns NSObject?
Defaults["anything"].number         // returns NSNumber?

When you don't want to deal with the nil case, you can use these helpers that return a default value for non-existing defaults:

Defaults["color"].stringValue            // defaults to ""
Defaults["launchCount"].intValue         // defaults to 0
Defaults["chimeVolume"].doubleValue      // defaults to 0.0
Defaults["loggingEnabled"].boolValue     // defaults to false
Defaults["lastPaths"].arrayValue         // defaults to []
Defaults["credentials"].dictionaryValue  // defaults to [:]
Defaults["hotkey"].dataValue             // defaults to NSData()

Installation

The simplest way to install this library is to copy SwiftyUserDefaults/SwiftyUserDefaults.swift to your project. There's no step two!

CocoaPods

You can also install this library using CocoaPods. Just add this line to your Podfile:

pod 'SwiftyUserDefaults'

Then import library module like so:

import SwiftyUserDefaults

Carthage

Just add to your Cartfile:

github "radex/SwiftyUserDefaults"

More like this

If you like SwiftyUserDefaults, check out SwiftyTimer, which applies the same swifty approach to NSTimer.

You might also be interested in my blog posts which explain the design process behind those libraries:

• Swifty APIs: NSUserDefaults
• Statically-typed NSUserDefaults
• Swifty APIs: NSTimer
• Swifty methods

Contributing

If you have comments, complaints or ideas for improvements, feel free to open an issue or a pull request. Or ping me on Twitter.

Author and license

Radek Pietruszewski

• github.com/radex
• twitter.com/radexp
• radex.io
• this.is@radex.io

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