TypedKey

Statically-typed key for Swift.

Design Goal

A design goal of TypedKey is to provide statically typed key-value interface to Cocoa APIs.

At a Glance

Key Definition

let myKey = Key<String, Int>("myKey")
myKey.key // "myKey"
myKey.keyType // `String`
myKey.valueType // `Int`

NSUserDefaults

let userIDKey = StringKey<Int>("userID")
NSUserDefaults.standardUserDefaults().setObject(10, forKey: userIDKey)
NSUserDefaults.standardUserDefaults().objectForKey(userIDKey) // statically typed `Int?`

UITableView

let userCellIdentifier = StringKey<UserCell>("userCell")
tableView.registerCell(userCellIdentifier)
tableView.dequeueCell(userCellIdentifier) // statically typed `UserCell?`

UICollectionView

let photoCellIdentifier = StringKey<PhotoCell>("photoCell")
collection.registerCell(photoCellIdentifier)
collection.dequeueCell(photoCellIdentifier, forIndexPath: ...) // statically typed `PhotoCell?`

Anything Else?

Pull requests are welcomed 💖

Advanced Usage

Creating Custom Typed Key

To create your custom typed key, you should implement TypedKey protocol. For example, this is how StringKey is implemented:

public struct StringKey<Value>: TypedKey {
    public typealias KeyType = String
    public typealias ValueType = Value

    public let key: KeyType
    public init(_ key: KeyType) {
        self.key = key
    }
}

Creating Custom Interface

You can make static typing key-value interface with TypedKey. Functions should use generic with type constraint on TypedKey. A type of the value can be inferred from the generic by using ValueType.

func set<T: TypedKey>(key: T, value: T.ValueType) {
    // do something great
}

A protocol TypedKey has two type aliases: KeyType and ValueType. You can make generic constraints on it.

func set<T: TypedKey where T.KeyType == String, T.ValueType: AnyObject>(key: T, value: T.ValueType) {
    // do something great with String key and AnyObject value
}

Installation

• For iOS 8+ projects with CocoaPods:

  pod 'TypedKey', '~> 0.1.0'

• For iOS 8+ projects with Carthage:

  github "devxoul/TypedKey" ~> 0.1.0
  

• For iOS 7 projects with CocoaSeeds:

  github 'devxoul/TypedKey', '0.1.0', :files => 'Sources/*.swift'

• Using Swift Package Manager:

  import PackageDescription
  
  let package = Package(
      name: "MyAwesomeApp",
      dependencies: [
          .Package(url: "https://github.com/devxoul/TypedKey", "0.1.0"),
      ]
  )

License

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