swift-keypaths-extensions

Extensions for Swift KeyPaths. Currently this package contains helpers for managing KeyPaths with Optional values, if you need extensions for enums, take a look at pointfreeco/swift-case-paths

Usage

struct Root {
  struct Property {
    var intValue: Int = 0
  }
  
  var optionalProperty: Property?
  
  init(_ value: Int?) {
    self.optionalProperty = value.map(Property.init(intValue:))
  }
}

// available out-of-the-box, recommended way when available
let kp_expression: KeyPath<Root, Int?> = \Root.optionalProperty?.intValue

// if you have 2 arbitrary paths
// and kp_1.Value.Type doesn't match kp_2.Value.Type exactly
// (Optionality causes mismatch in that case)
let kp_1: KeyPath<Root, Property?> = \Root.optionalProperty
let kp_2: KeyPath<Property, Int> = \Property.intValue
  
// `kp_1.appending(path: kp_2)` is not available out-of-the-box
let kp_combined: KeyPath<Root, Int?> = kp_1.appending(kp_2)

// unwrapping is not available out-of-the-box
let kp_unwrapped: KeyPath<Root, Int> = kp_combined.unwrapped(with: 0)

// ⚠️ tho unwrapped paths shouldn't be combined for reference types

Note

Take a look at tests for more examples. Also keep your eye on doc comments for more info.

Installation

Basic

You can add KeypathsExtensions to an Xcode project by adding it as a package dependency.

1. From the File menu, select Swift Packages › Add Package Dependency…
2. Enter "https://github.com/capturecontext/swift-keypaths-extensions" into the package repository URL text field
3. Choose products you need to link them to your project.

Recommended

If you use SwiftPM for your project structure, add KeyPathsExtensions to your package file.

.package(
  url: "[email protected]:capturecontext/swift-keypaths-extensions.git", 
  .upToNextMinor(from: "0.0.1")
)

or via HTTPS

.package(
  url: "https://github.com:capturecontext/swift-keypaths-extensions.git", 
  .upToNextMinor("0.0.1")
)

Do not forget about target dependencies:

.product(
  name: "KeyPathsExtensions", 
  package: "swift-keypaths-extensions"
)

License

This library is released under the MIT license. See LICENSE for details.