Shark

Shark is a Swift command line tool that generates type safe enums for your images, colors, storyboards, fonts and localizations. Shark supports code generation for the Apple UI frameworks UIKit, AppKit, and SwiftUI.

Because Shark reads your .xcodeproj to find these assets, the setup is extremely simple.

WWDC 2023 NEWS Although Shark has been a bit sherlocked by the new Color and Image resources in Xcode 15, there's still no support for fonts, storyboards, and localizations. We will therefore continue to maintain Shark!

Motivation

Here's what a generated Shark.swift file for UIKit looks like and how it is used in a codebase:

// Shark.swift
// Generated by Shark https://github.com/kaandedeoglu/Shark

import UIKit

// swiftlint:disable all
public enum Shark {
    private static let bundle: Bundle = {
        class Custom {}
        return Bundle(for: Custom.self)
    }()

    public enum I {
        public enum Button {
            public static var profile: UIImage { return UIImage(named:"profile", in: bundle, compatibleWith: nil)! }
            public static var cancel: UIImage { return UIImage(named:"cancel", in: bundle, compatibleWith: nil)! }
            public static var user_avatar: UIImage { return UIImage(named:"user_avatar", in: bundle, compatibleWith: nil)! }
        }
    }

    public enum C {
        public static var blue1: UIColor { return UIColor(named: "blue1", in: bundle, compatibleWith: nil)! }
        public static var blue2: UIColor { return UIColor(named: "blue2", in: bundle, compatibleWith: nil)! }
        public static var gray1: UIColor { return UIColor(named: "gray1", in: bundle, compatibleWith: nil)! }
        public static var gray2: UIColor { return UIColor(named: "gray2", in: bundle, compatibleWith: nil)! }
        public static var green1: UIColor { return UIColor(named: "green1", in: bundle, compatibleWith: nil)! }
        public static var green2: UIColor { return UIColor(named: "green2", in: bundle, compatibleWith: nil)! }
    }

    public enum F {
        public static func gothamBold(ofSize size: CGFloat) -> UIFont { return UIFont(name: "Gotham-Bold", size: size)! }
        public static func gothamMedium(ofSize size: CGFloat) -> UIFont { return UIFont(name: "Gotham-Medium", size: size)! }
        public static func gothamRegular(ofSize size: CGFloat) -> UIFont { return UIFont(name: "Gotham-Regular", size: size)! }
    }

    public enum L {
        public enum button {
            /// Login
            public static var login: String { return NSLocalizedString("button.login", bundle: bundle, comment: "") }

            /// Logout
            public static var logout: String { return NSLocalizedString("button.logout", bundle: bundle, comment: "") }
        }

        public enum login {
            /// Please log in to continue
            public static var title: String { return NSLocalizedString("login.title", bundle: bundle, comment: "") }

            /// Skip login and continue
            public static var skip: String { return NSLocalizedString("login.skip", bundle: bundle, comment: "") }

            public enum error {
                /// Login failed
                public static var title: String { return NSLocalizedString("login.error.title", bundle: bundle, comment: "") }

                /// Operation failed with error: %@
                public static func message(_ value1: String) -> String {
                    return String(format: NSLocalizedString("login.error.message", bundle: bundle, comment: ""), value1)
                }
            }
        }
    }
}

// At the call site
imageView.image = Shark.I.Button.profile
label.font = Shark.F.gothamBold(ofSize: 16.0)
label.text = Shark.L.login.title
view.backgroundColor = Shark.C.green1

// You can also make it prettier with typealiases
typealias I = Shark.I
typealias C = Shark.C
typealias F = Shark.F
typealias L = Shark.L

imageView.image = I.Button.profile
label.font = F.gothamBold(ofSize: 16.0)
label.text = L.login.error.message("I disobeyed my masters")
view.backgroundColor = C.green1

There are a few things to notice:

First, have a look at this Xcode screenshot from the inspector pane of an asset catalogue's folder entry:

If you place your image and color assets in folders, Shark will create namespaced enums ­– provided you have configured the respective Xcode setting Provides Namespace. If you have deeply nested folders, Shark will respect every one's individual namespace setting.

Localizations are always namespaced with separators. Currently Shark uses the dot symbol . as the separator. As you can see localization keys are recursively namespaced until we get to the last component.

Installation

Homebrew

brew install kaandedeoglu/formulae/shark

Mint

mint install kaandedeoglu/formulae/shark

Manually

Clone the project, then do:

> swift build -c release
> cp ./build/release/Shark /usr/local/bin

You can then verify the installation by doing

> shark --help

Setup

• Add a new Run Script phase to your target's build phases. This build phase should ideally run before the Compile Sources phase. The script body should look like the following:

  if [ -x "$(command -v shark)" ]; then
  shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME/
  fi

  the if/fi block makes sure that Shark runs only if it's installed on the current machine.

• Build your project. You should now see a file named Shark.swift in your project folder.

• Add this file to your target. Voila! Shark.swift will be updated every time you build the project.

• Alternatively you can do the following:

  # Write to a specific file called MyAssets.swift
  shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME/MyAssets.swift

  # Write to a specific file in a different folder
  shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME/Utility/MyAssets.swift

Options & Flags

Shark also accepts the following command line options to configure behavior

--name

By default, the top level enum everything else lives under is called - you guessed it - Shark. You can change this by using the --name flag.

 shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME --name Assets

--locale

By default, Shark will try to find English localizations to generate the localizations enum. If there are no English .strings file in your project, or you'd like Shark to take another localization as base, you can specify the language code with the --locale flag.

# Use Spanish localizations for generation
shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME --locale es

--target

In case your Xcode project has multiple application targets, you should specify which one Shark should look at by using the --target flag.

shark $PROJECT_FILE_PATH $PROJECT_DIR/$PROJECT_NAME --target MyAppTarget

--visibility

By default, Shark will create all properties with the visibilty of public. Submit this option to change this to, e.g., internal.

--framework

By default, Shark creates code for UIKit. Specify --framework appkit to create code for AppKit, and --framework swiftui for SwiftUI.

--separator

Shark will split localization keys using the separator character value, and create nested enums until we hit the last element. For example, the lines login.button.positive = "Log in!"; and login.button.negative = "Go back..."; will create the following structure inside the top level localizations enum L:

public enum login {
    public enum button {
        public static var positive: String { return NSLocalizedString("login.button.positive") }
        public static var negative: String { return NSLocalizedString("login.button.negative") }
    }
}

By default, the separator is ., only single character inputs are accepted for this option.

--top-level-scope

Declares the I, C, F, L enums in the top level scope instead of nesting it in a top level Shark enum.

--exclude

By default, Shark will process all resource files it knows about. If you don't want that, you can specify exceptions. Note that Shark uses suffix matching to identify files to exclude.

--help

Prints the overview, example usage and available flags to the console.

License

The MIT License (MIT)

Copyright (c) Kaan Dedeoglu, Dr. Michael 'Mickey' Lauer, and contributors.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.