Building Custom Token Transformers

1. Introduction

In modern design systems, design tokens serve as the foundation for consistent theming. This lesson will guide you through the process of building custom token transformers, which allow you to manipulate design tokens according to specific requirements.

2. Key Concepts

Before diving into the practical steps, it's essential to understand some key concepts:

• Design Tokens: These are the visual design atoms of the UI, representing color, spacing, typography, etc.
• Transformers: Functions or methods that convert design tokens into usable formats or apply transformations.
• Theming Systems: Frameworks that leverage design tokens to create adaptable and consistent UI themes.

3. Step-by-Step Process

Here is a structured process to build custom token transformers:

1. Define your design tokens in a structured format (e.g., JSON).
2. Create a transformer function to manipulate these tokens.
3. Integrate the transformer within your theming system.
4. Test the transformations to ensure they meet design specifications.

Example: Transformer Function

function scaleTokens(tokens, scaleFactor) {
    return Object.keys(tokens).reduce((acc, key) => {
        acc[key] = tokens[key] * scaleFactor;
        return acc;
    }, {});
}
        

This function scales numeric design tokens by a given scale factor.

Example: Integrating Transformer

const tokens = {
    spacing: 8,
    fontSize: 16,
};

const scaledTokens = scaleTokens(tokens, 2);
console.log(scaledTokens); // { spacing: 16, fontSize: 32 }
        

4. Best Practices

Follow these best practices when building custom token transformers:

• Ensure your transformers are reusable and modular.
• Document your tokens and transformers for better collaboration.
• Maintain a consistent naming convention for tokens and functions.
• Test transformers with various inputs to cover edge cases.

5. FAQ