@tokens-studio/sd-transforms

Style Dictionary Transforms for Tokens Studio

Table of contents

• Installation
• Getting Started
  • Using the transforms
  • Custom Transform Group
  • Options
• Full example
  • Themes full example
  • Multi-dimensional theming
• Troubleshooting

This library is currently in beta.

This package contains custom transforms for Style-Dictionary, to work with Design Tokens that are exported from Tokens Studio:

Generic:

• Expands composition tokens into multiple, optionally also does so for typography, border and shadow tokens -> parser
• Optionally excludes parent keys from your tokens file, e.g. when using single-file export from Tokens Studio Figma plugin -> parser
• Maps token descriptions to comments -> ts/descriptionToComment
• Check and evaluate Math expressions (transitive) -> ts/resolveMath
• Transform dimensions tokens to have px as a unit when missing (transitive) -> ts/size/px
• Transform opacity from % to number between 0 and 1 -> ts/opacity
• Transform lineheight from % to unitless (150% -> 1.5) -> ts/size/lineheight
• Transform fontweight from keynames to fontweight numbers (100, 200, 300 ... 900) -> ts/typography/fontWeight
• Transform color modifiers from Tokens Studio to color values -> ts/color/modifiers

CSS:

• Transform letterspacing from % to em -> ts/size/css/letterspacing
• Transform colors to rgba() format -> ts/color/css/hexrgba
• Transform font family into valid CSS, adding single quotes if necessary -> ts/typography/css/fontFamily
• Transform typography objects to CSS shorthand -> ts/typography/css/shorthand
• Transform Tokens Studio shadow objects to CSS shadow shorthand -> ts/shadow/css/shorthand
• Transform border objects to CSS border shorthand -> ts/border/css/shorthand

Android:

• Transform typography objects to Android Compose shorthand -> ts/typography/compose/shorthand

Registers the generic and CSS transforms, in addition to name/cti/camel for naming purposes, as a transform group called tokens-studio.

Installation

With NPM:

npm install @tokens-studio/sd-transforms

Usage

Note: this library is available both in CJS and ESM

const { registerTransforms } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');

// will register them on StyleDictionary object
// that is installed as a dependency of this package.
registerTransforms(StyleDictionary);

Can also import in ESM if needed.

Using the transforms

In your Style-Dictionary config, you can either use the tokens-studio transformGroup or the separate transforms (all of the names of those are listed):

{
  "source": ["**/*.tokens.json"],
  "platforms": {
    "css": {
      "transformGroup": "tokens-studio",
      "buildPath": "build/css/",
      "files": [
        {
          "destination": "variables.css",
          "format": "css/variables"
        }
      ]
    }
  }
}

More fine-grained control is possible, every transformation is available as a raw JavaScript function for you to create your own Style-Dictionary transformer out of.

const { transformDimension } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');

StyleDictionary.registerTransform({
  name: 'my/size/px',
  type: 'value',
  transitive: true,
  matcher: token => ['fontSizes', 'dimension', 'borderRadius', 'spacing'].includes(token.type),
  transformer: token => transformDimension(token.value),
});

Custom Transform Group

In Style-Dictionary, transformGroup and transforms cannot be combined in a platform inside your config.

Therefore, if you wish to use the transform group, but adjust, add or remove a few transforms, your best option is creating a custom transformGroup:

const { transforms } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');

// Register custom tokens-studio transform group
// without 'px' being added to numbers without a unit
// and also adding 'name/cti/camel' for the token names
StyleDictionary.registerTransformGroup({
  name: 'custom/tokens-studio',
  transforms: [...transforms, 'name/cti/camel'].filter(transform => transform !== 'ts/size/px'),
});

Options

You can pass options to the registerTransforms function.

registerTransforms({
  expand: {
    composition: false,
    typography: true,
    border: (token, filePath) =>
      token.value.width !== 0 && filePath.startsWith(path.resolve('tokens/core')),
    shadow: false,
  },
  excludeParentKeys: true,
  'ts/color/modifiers': {
    format: 'hex',
  },
});

Options:

name	type	required	default	description
excludeParentKeys	boolean	❌	false	Whether or not to exclude parent keys from your token files
alwaysAddFontStyle	boolean	❌	false	Whether or not to always add a 'normal' fontStyle property to typography tokens which do not have explicit fontStyle
casing	string	❌	camel	What kind of casing to use for token names. Options: [camel, pascal, snake, kebab, constant]
expand	boolean | ExpandOptions	❌	See props below	false to not register the parser at all. By default, expands composition tokens. Optionally, border, shadow and typography as well.
expand.composition	boolean | ExpandFilter	❌	true	Whether or not to expand compositions. Also allows a filter callback function to conditionally expand per token/filePath
expand.typography	boolean | ExpandFilter	❌	false	Whether or not to expand typography. Also allows a filter callback function to conditionally expand per token/filePath
expand.shadow	boolean | ExpandFilter	❌	false	Whether or not to expand shadows. Also allows a filter callback function to conditionally expand per token/filePath
expand.border	boolean | ExpandFilter	❌	false	Whether or not to expand borders. Also allows a filter callback function to conditionally expand per token/filePath
['ts/color/modifiers']	ColorModifierOptions	❌	See props below	Color modifier options
['ts/color/modifiers'].format	ColorModifierFormat	❌	undefined	Color modifier output format override ('hex' | 'hsl' | 'lch' | 'p3' | 'srgb'), uses local format or modifier space as default

Note: you can also import and use the expandComposites function to run the expansion on your token object manually. Handy if you have your own parsers set up (e.g. for JS files), and you want the expansions to work there too.

Full example

Create a .js file, e.g.: build-output.js, with the contents:

const { registerTransforms } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');

registerTransforms(StyleDictionary);

const sd = StyleDictionary.extend({
  source: ['**/*.tokens.json'],
  platforms: {
    js: {
      transformGroup: 'tokens-studio',
      buildPath: 'build/js/',
      files: [
        {
          destination: 'variables.js',
          format: 'javascript/es6',
        },
      ],
    },
    css: {
      transforms: [
        'ts/descriptionToComment',
        'ts/size/px',
        'ts/opacity',
        'ts/size/lineheight',
        'ts/typography/fontWeight',
        'ts/resolveMath',
        'ts/size/css/letterspacing',
        'ts/typography/css/fontFamily',
        'ts/typography/css/shorthand',
        'ts/border/css/shorthand',
        'ts/shadow/css/shorthand',
        'ts/color/css/hexrgba',
        'ts/color/modifiers',
        'name/cti/kebab',
      ],
      buildPath: 'build/css/',
      files: [
        {
          destination: 'variables.css',
          format: 'css/variables',
        },
      ],
    },
  },
});

sd.cleanAllPlatforms();
sd.buildAllPlatforms();

To run it use following command

node build-output.js

Note: make sure to choose either the full transformGroup, OR its separate transforms so you can adjust or add your own. Combining a transformGroup with a transforms array can give unexpected results.

Themes full example

You might be using Themes in the PRO version of Tokens Studio.

Here's a full example of how you can use this in conjunction with Style Dictionary and sd-transforms:

Run this script:

const { registerTransforms } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');
const { promises } = require('fs');

registerTransforms(StyleDictionary, {
  /* options here if needed */
});

async function run() {
  const $themes = JSON.parse(await promises.readFile('$themes.json', 'utf-8'));
  const configs = $themes.map(theme => ({
    source: Object.entries(theme.selectedTokenSets)
      .filter(([, val]) => val !== 'disabled')
      .map(([tokenset]) => `${tokenset}.json`),
    platforms: {
      css: {
        transformGroup: 'tokens-studio',
        files: [
          {
            destination: `vars-${theme.name}.css`,
            format: 'css/variables',
          },
        ],
      },
    },
  }));

  configs.forEach(cfg => {
    const sd = StyleDictionary.extend(cfg);
    sd.cleanAllPlatforms(); // optionally, cleanup files first..
    sd.buildAllPlatforms();
  });
}

run();

Multi-dimensional Theming

If you're using Tokens Studio multi-dimensional theming, you'll have to run some logic to create permutations of those multiple dimensions of themes. We export a function called permutateThemes that allows passing the data from your $themes.json, and will give back an object with all the different permutations.

const { permutateThemes } = require('@tokens-studio/sd-transforms');
const fs = require('fs');

/**
 * Input:
 * [
 *  {
 *    name: 'light'
 *    group: 'theme',
 *    selectedTokensets: {
 *      'core': 'source',
 *      'light': 'enabled',
 *      'theme': 'enabled'
 *    }
 *  },
 *  {
 *    name: 'dark'
 *    group: 'theme',
 *    selectedTokensets: {
 *      'core': 'source',
 *      'dark': 'enabled',
 *      'theme': 'enabled'
 *    }
 *  },
 *  {
 *    name: 'casual'
 *    group: 'brand',
 *    selectedTokensets: {
 *      'core': 'source',
 *      'casual': 'enabled'
 *    }
 *  },
 *  {
 *    name: 'business'
 *    group: 'brand',
 *    selectedTokensets: {
 *      'core': 'source',
 *      'business': 'enabled'
 *    }
 *  }
 * ]
 *
 * Output:
 * {
 *   light_casual: ['core', 'light', 'theme', 'casual'],
 *   dark_casual: ['core', 'dark', 'theme', 'casual'],
 *   light_business: ['core', 'light', 'theme', 'business'],
 *   dark_business: ['core', 'dark', 'theme', 'business'],
 * }
 */
permutateThemes(JSON.parse(fs.readFileSync('$themes.json', 'utf-8')), { seperator: '_' });

Full example with multi-dimensional themes:

const { registerTransforms, permutateThemes } = require('@tokens-studio/sd-transforms');
const StyleDictionary = require('style-dictionary');
const { promises } = require('fs');

registerTransforms(StyleDictionary, {
  /* options here if needed */
});

async function run() {
  const $themes = JSON.parse(await promises.readFile('$themes.json', 'utf-8'));
  const themes = permutateThemes($themes, { seperator: '_' });
  const configs = Object.entries(themes).map(([name, tokensets]) => ({
    source: tokensets.map(tokenset => `${tokenset}.json`),
    platforms: {
      css: {
        transformGroup: 'tokens-studio',
        files: [
          {
            destination: `vars-${name}.css`,
            format: 'css/variables',
          },
        ],
      },
    },
  }));

  configs.forEach(cfg => {
    const sd = StyleDictionary.extend(cfg);
    sd.cleanAllPlatforms(); // optionally, cleanup files first..
    sd.buildAllPlatforms();
  });
}

run();

Not sure how to fix your issue ?

Create a reproduction by :-

1. Open configurator tool link
2. Upload your tokens and add your style dictionary config and transforms
3. Copy the Url as it will include your settings.
4. Join our slack link
5. Open style-dictionary-configurator channel.
6. Create a thread about your issue and paste your reproduction link inside it.

Changelog

0.11.0

Minor Changes

• 96a66a9: checkAndEvaluateMath to not stringify if not needed:

  • for single math expressions resolving to a floating number without unit, we can keep it as a Number
  • for expressions such as false or true (Boolean), keep as Boolean type