Custom components are a fundamental part of modern development, especially in dynamic applications using frameworks like React, Angular, or Vue. However, these components can be problematic from an accessibility perspective if not implemented correctly.

In this chapter, we will explore how to design and develop accessible custom components using best practices, semantic HTML, and ARIA.

Why can custom components be problematic?

Custom components, like those created with <div> or <span>, lack the semantics and native behaviors that assistive technologies need to interpret them correctly. For example:

• A button made with <div> is not automatically keyboard accessible.
• A custom dropdown menu may lack logical navigation or defined roles.

Principles for accessible components

1. Use native labels whenever possible: Prefer <button>, <input>, and <select> instead of reinventing their functionality.
2. Add ARIA roles when necessary: Use roles to describe the function of the custom component.
3. Manage focus and navigation: Ensure the component is keyboard operable.
4. Provide visual feedback: Use clear indicators for states like focus, selection, or activation.

Example: Custom button

A custom button must be keyboard operable (Enter or Space) and provide an adequate role.

Non-accessible code:

html

Accessible code:

html

Example: Accessible dropdown menu

Dropdown menus need roles and states indicating whether they are open or closed.

Accessible code:

html

Using frameworks for accessible components

Many frameworks offer libraries that help create accessible components, such as:

• React ARIA: Provides hooks for accessibility in React components.
• Angular Material: Includes accessible components by default.
• Vue A11y: Plugins to improve accessibility in Vue.

Example with React:

javascript

Testing and tools for custom components

Test with tools like:

• Axe DevTools: Analyzes the accessibility of your components in real-time.
• Storybook: Test components in isolation.
• Testing Library: Write unit tests to verify accessibility.

Testing example with Testing Library:

javascript

Conclusion

Creating accessible custom components requires a deep understanding of semantic HTML, ARIA, and user needs. By following best practices and conducting thorough testing, you can ensure that even the most advanced components are inclusive.

This content complements the course and reinforces the importance of accessibility throughout the development process. Keep creating inclusive digital experiences!