jlawton / Cataloger

Outputs constants to reference xcassets in your code

Cataloger

cataloger is a simple utility for creating constants from framework assets.

This has a few potential benefits, including:

• if you add and remove assets, you can keep your code up-to-date with a cataloger build phase.
• you get compile errors for invalid asset names, and autocompletion of valid names.
• it's easy to expose your assets to consumers outside of your framework.

Usage

Create a Swift file describing the assets in an asset catalog. Once a catalog has been compiled, it is opaque. Apple has not published the format of a .car and I'm not interested in figuring it out, since the source folder is a much simpler route to the same information.

$ cataloger generate <path/to/Images.xcassets>

Create a Swift file describing the assets in a framework.

$ cataloger generate <path/to/Framework.framework>

Options

There are a few command line options currently available. For example:

$ cataloger generate \
    --name 'SomeFrameworkAsset' \
    --type 'enum' \
    --bundle-class 'SomeFrameworkClass' \
    path/to/Images.xcassets

This would define a String-backed Swift enum, named SomeFrameworkAsset, with cases for the image assets found in path/to/Images.xcassets. It would also generate an image accessor, which looks up the assets in the in which the class SomeFrameworkClass is defined.

See cataloger help generate for more details.

Name Mangling

cataloger takes the names of assets and turns them into Swift constants. It's not very intelligent about this right now, but should work for common naming schemes.

For instance, an image which you would normally load with:

let icon = UIImage(named: "icon/friendly_face", in: Bundle(for: SomeFrameworkClass.self), compatibleWith: nil)!

might be accessed like:

let icon = SomeFrameworkAsset.iconFriendlyFace.image

Limitations

Currently, cataloger only really handles image assets. It is in early development, and there are useful features yet to be implemented.