R.swift

Tool to get strong typed, autocompleted resources like images and segues in Swift

Why use this?

Normally you access your images, segues or storyboards based on strings, like UIImage(names: "settings-icon") or performSegueWithIdentifier("openSettings"). This is fragile since the compiler can't warn you about using the wrong identifier.

With R.swift we make sure you can use strong typed identifiers like R.image.someIcon or R.segue.openSettings to get your image or segue identifier, the R-struct will be automatically update on build. So it's never outdated and you will get compiler errors if you rename or delete a resource.

Usage

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 If the struct is outdated just build and R.swift will correct any missing/changed/added resources. Below you find the different formats:

Type	Format	Without R.swift	With R.swift
Image	R.image.[imageName]	UIImage(named: "settings-icon")	R.image.settingsIcon
Segue	R.segue.[segueIdentifier]	"openSettingsSegue"	R.segue.openSettingsSegue
Storyboard	R.storyboard.[storyboardName].instance	UIStoryboard(name: "Main", bundle: nil)	R.storyboard.main.instance
ViewController	R.storyboard.[storyboardName].[viewControllerIdentifier]	UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("LoginController") as? LoginController	R.storyboard.main.loginController

Validate usage of images in Storyboards with R.validate() or to validate a specific storyboard use R.storyboard.[storyboardName].validateImages(). Please note that this uses assert and will only work in unoptimized debug builds.

Installation

1. Download a R.swift release, unzip it and put it into your source root directory
2. In XCode: Click on your project in the file list, choose your target under TARGETS, click the Build Phases tab and add a New Run Script Phase by clicking the little plus icon in the top left
3. Drag the new Run Script phase above the Compile Sources phase, expand it and paste the following script: "$SRCROOT/rswift" "$SRCROOT"
4. Build your project, in Finder you will now see a R.generated.swift in the $SRCROOT-folder, drag the R.generated.swift files into your project and uncheck Copy items if needed

Tip: Add the *.generated.swift pattern to your .gitignore file to prevent unnecessary conflicts.

Tips and tricks

Running R.swift gives errors like 29593 Trace/BPT trap: 5, how to fix them?

Make sure you run OS X 10.10 or higher with XCode 6.1+. Lower versions are not supported and could lead to errors like these.

R.swift also picks up asset files/storyboards from submodules and CocoaPods, can I prevent this?

You can by changing the second argument ("$SRCROOT" in the example) of the build phase script, this is the folder R.swift will scan through. If you make this your project folder by changing the script to "$SRCROOT/rswift" "$SRCROOT/MyProject" it will only scan that folder.

Can I make R.swift scan multiple folder trees?

You can by passing multiple folders to scan through. Change the build phase script to something like this: "$SRCROOT/rswift" "$SRCROOT/MyProject" "$SRCROOT/SubmoduleA" "$SRCROOT/SubmoduleB". Each folder will get it's own R.generated.swift file since R.swift assumes these folders will be different subprojects.

When I launch rswift from Finder I get this "Unknown developer warning"?!

For now I'm to lazy to sign my builds with a Developer ID and when running stuff from the commandline/XCode it's not a problem. It will just work, but maybe I'll fix this. Signed releases are nice, now I only need to find some time to fix this. :)

Contribute

Please post any issues, ideas and compliments in the GitHub issue tracker and feel free to submit pull request with fixes and improvements. Keep in mind; a good pull request is small, well explained and should benifit most of the users.

License

R.swift is released under MIT License and created by Mathijs Kadijk.