Resourceful

Resourceful is an Xcode utility that helps avoid making mistakes when using UIImage/NSImage imageNamed:. That method takes a String, and loads an image from your app's bundle with that name. Unfortunately, there's no warning if you, say, typo the string.

Resourceful skirts this issue by inspecting your Xcode project for image assets, and creating an enum of all of their possible values. Thus,

let image = UIImage(named: "catsInSpace")

becomes

let image = Resource.Image.CatsInSpace.image

There are many other libraries that do this, but this one is mine. Why should you use it instead of anything else?

• It's written in Go, and really fast (important for a program that you'll be running as part of every Xcode build)
• It works for both iOS and OS X projects
• It can optionally generate warnings for you in places where you're still using imageNamed in your app.

Getting started

First, install Resourceful:

cd /usr/local/bin
curl -L -O https://github.com/jflinter/Resourceful/releases/download/0.2/resourceful.tar.gz
tar -zxvf resourceful.tar.gz

Next, in your Xcode build phases settings, add a new Run Script Build Phase at the beginning of your build. For its contents, simply type

resourceful

In the "Input Files" section, put a link to your app's Images.xcassets directory. This will typically be:

$(SRCROOT)/Your_apps_name/Images.xcassets

In the "Output Files" section, specify where you'd like the code Resourceful generates to live. This will typically be:

$(SRCROOT)/Your_apps_name/Resourceful.swift

If you're wondering, you specify your files this way because Xcode can then intelligently avoid re-running this script unless the contents of your Images.xcassets changes.

Next, build your app. This will generate Resourceful.swift at the directory you specified.

Finally, add Resourceful.swift to your Xcode project by going to File -> Add Files to "Your app's name".

Optional

As mentioned previously, Resourceful can also generate warnings in your Xcode project to encourage you to stop using imageNamed. To do this, add another Run Script Build Phase (it needs to be separate from the previous script, in case Xcode skips the previous one due to caching) with the contents:

resourceful warn

And you're done!