R.swift

Get strong typed, autocompleted resources like images, fonts and segues in Swift projects

Why use this?

It makes your code that uses resources:

• Fully typed, less casting and guessing what a method will return
• Compile time checked, no more incorrect strings that make your app crash at runtime
• Autocompleted, never have to guess that image name again

Currently you type:

let icon = UIImage(named: "settings-icon")
let font = UIFont(name: "San Francisco", size: 42)
let color = UIColor(named: "indicator highlight")
let viewController = CustomViewController(nibName: "CustomView", bundle: nil)
let string = String(format: NSLocalizedString("welcome.withName", comment: ""), locale: NSLocale.current, "Arthur Dent")

With R.swift it becomes:

let icon = R.image.settingsIcon()
let font = R.font.sanFrancisco(size: 42)
let color = R.color.indicatorHighlight()
let viewController = CustomViewController(nib: R.nib.customView)
let string = R.string.localizable.welcomeWithName("Arthur Dent")

Check out more examples or hear about how Fabric.app uses R.swift!

Demo

Autocompleted images:

Compiletime checked images:

This is only the beginning, check out more examples!

CocoaHeadsNL presentation

Mathijs Kadijk presented R.swift at the September 2016 CocoaHeadsNL meetup. Talking about the ideas behind R.swift and demonstrating how to move from plain stringly-typed iOS code to statically typed code.

Features

After installing R.swift into your project you can use the R-struct to access resources. If the struct is outdated just build and R.swift will correct any missing/changed/added resources.

R.swift currently supports these types of resources:

• Images
• Fonts
• Resource files
• Colors
• Localized strings
• Storyboards
• Segues
• Nibs
• Reusable cells

Runtime validation with R.validate():

• If all images used in storyboards and nibs are available
• If all named colors used in storyboards and nibs are available
• If all view controllers with storyboard identifiers can be loaded
• If all custom fonts can be loaded

Q&A

• Why was R.swift created?
• Why should I choose R.swift over alternative X or Y?
• What are the requirements to run R.swift?
• How to use methods with a Void argument?
• How to fix missing imports in the generated file?
• How to use classes with the same name as their module?
• Can I ignore resources?
• Can I use R.swift in a library?
• How does R.swift work?
• How to upgrade to a new major version?
• How can I only run specific generators?

Installation

As of Rswift 7, Swift Package Manager is the recommended method of installation.

Demo video: Updating from R.swift 6 to Rswift 7 (Starting at 1:06, this describes the installation of Rswift 7).

Xcode project - SPM

1. In Project Settings, on the tab “Package Dependencies”, click “+” and add github.com/mac-cain13/R.swift
2. Select your target, on the tab “General”, in the section “Frameworks, Libraries, and Embeded Content”, click “+” and add RswiftLibrary
3. Select your target, on the tab “Build Phases”, in the section “Run Build Tool Plug-ins”, click “+” and add RswiftGenerateInternalResources
4. Build your project, now the R struct should be available in your code, use auto-complete to explore all static references

Screenshot of the Build Phase can be found here

When running on Xcode Cloud

1. Add a custom build script in ci_scripts/ci_post_clone.sh with the content: defaults write com.apple.dt.Xcode IDESkipPackagePluginFingerprintValidatation -bool YES

Package.swift based SPM project

1. Add a dependency in Package.swift:

   dependencies: [
       .package(url: "https://github.com/mac-cain13/R.swift.git", from: "7.0.0")
   ]
   

2. For each relevant target, add a dependency and a plugin

   .target(
       name: "Example",
       dependencies: [.product(name: "RswiftLibrary", package: "R.swift")],
       plugins: [.plugin(name: "RswiftGeneratePublicResources", package: "R.swift")]
   )
   

3. Build your project, now the R struct should be available in your code, use auto-complete to explore all static references

Contribute

We’ll love contributions, read the contribute docs for info on how to report issues, submit ideas and submit pull requests!

License

R.swift and R.swift.Library are created by Mathijs Kadijk and released under a MIT License.

Special thanks to Tom Lokhorst for his major contributions and help maintaining this project.