Dynamic Theme Switching with JavaScript

1. Introduction

Dynamic theme switching allows users to change the visual appearance of an application in real-time. This is often achieved through the use of design tokens, which are the visual design atoms of a product's UI.

2. Design Tokens

Design tokens are named entities that store visual design attributes. They can represent colors, typography, spacing, etc., in a consistent manner.

        const designTokens = {
            light: {
                background: '#ffffff',
                color: '#000000',
            },
            dark: {
                background: '#000000',
                color: '#ffffff',
            }
        };
        

3. Dynamic Theme Switching

To implement dynamic theme switching, we can apply the following steps:

1. Define your design tokens.
2. Create a function to apply the selected theme.
3. Add event listeners to theme switch buttons.
4. Persist user preferences using local storage.

        // Step 1: Define your design tokens
        const designTokens = {
            light: {
                background: '#ffffff',
                color: '#000000'
            },
            dark: {
                background: '#000000',
                color: '#ffffff'
            }
        };

        // Step 2: Apply the theme
        function applyTheme(theme) {
            const { background, color } = designTokens[theme];
            document.body.style.backgroundColor = background;
            document.body.style.color = color;
            localStorage.setItem('theme', theme);
        }

        // Step 3: Event listeners
        document.getElementById('light-theme').addEventListener('click', () => applyTheme('light'));
        document.getElementById('dark-theme').addEventListener('click', () => applyTheme('dark'));

        // Step 4: Persist user preference
        const savedTheme = localStorage.getItem('theme') || 'light';
        applyTheme(savedTheme);
        

4. Best Practices

• Use semantic HTML for theme switch buttons.
• Test themes with real users for accessibility.
• Store user preferences persistently.

5. FAQ