ai-for-dummies/submitted-skills/Leonardo Uno/SKILL.md

name, description

name	description
angular-accessibility	Enforce and improve accessibility (a11y) in Angular applications following WCAG 2.2 AA, ARIA best practices, semantic HTML, and Angular-specific patterns.

Angular Accessibility Skill

Purpose

This skill helps build and review Angular applications that are accessible by default. It prioritizes semantic HTML, keyboard navigation, screen reader compatibility, color contrast, focus management, and Angular CDK accessibility utilities.

Target standard: WCAG 2.2 Level AA

When to Use

Activate this skill whenever the task involves:

• Creating Angular components
• Reviewing templates for accessibility
• Refactoring UI components
• Building forms
• Navigation menus
• Dialogs and modals
• Tables
• Custom controls
• Angular Material components
• Accessibility audits
• Fixing Lighthouse or axe-core accessibility issues

---

Accessibility Principles

Always follow this priority order:

1. Semantic HTML
2. Native browser behavior
3. Angular accessibility utilities
4. ARIA only when necessary

Rule: Never use ARIA to replace native HTML functionality.

Example:

Good:

<button type="button">Save</button>

Avoid:

<div role="button">Save</div>

---

Angular Template Rules

Buttons

Always:

• use <button>
• specify type
• provide accessible text

Good:

<button type="submit">Submit</button>

Icon button:

<button type="button" aria-label="Close dialog">
  <mat-icon>close</mat-icon>
</button>

---

Links

Use <a> only for navigation.

Good:

<a routerLink="/dashboard">Dashboard</a>

Avoid:

<a (click)="save()">Save</a>

Use a button instead.

---

Images

Decorative:

<img src="divider.svg" alt="">

Informative:

<img src="profile.jpg" alt="Jane Doe smiling">

Avoid generic alt text like "image" or "photo."

---

Forms

Labels

Every input needs a label.

Good:

<label for="email">Email</label>
<input id="email" type="email">

Angular Material:

<mat-form-field>
  <mat-label>Email</mat-label>
  <input matInput type="email">
</mat-form-field>

---

Error Messages

Requirements:

• visible
• descriptive
• associated with the input

Example:

<input
  id="email"
  aria-describedby="email-error">

<div id="email-error">
  Enter a valid email address.
</div>

Avoid relying on color alone.

---

Required Fields

Use both:

<input required aria-required="true">

---

Keyboard Accessibility

Every interactive element must be usable with:

• Tab
• Shift+Tab
• Enter
• Space
• Escape (when applicable)
• Arrow keys (where expected)

Never trap keyboard focus.

---

Focus Management

Use Angular CDK when possible.

Example:

constructor(private focusMonitor: FocusMonitor) {}

For dialogs:

• move focus into dialog
• trap focus
• restore focus on close

Angular Material already provides this behavior.

---

Angular CDK Accessibility

Prefer Angular CDK utilities.

Useful services:

• FocusMonitor
• LiveAnnouncer
• InteractivityChecker
• FocusTrapFactory

Example:

this.liveAnnouncer.announce('Settings saved');

Use for:

• success messages
• validation updates
• dynamic content

---

ARIA Usage

Use ARIA only when native HTML cannot express the behavior.

Common attributes:

Attribute	Use
aria-label	Icon buttons
aria-labelledby	Existing visible label
aria-describedby	Helper/error text
aria-expanded	Expandable controls
aria-controls	Controlled region
aria-live	Dynamic announcements
aria-current	Current navigation item

Avoid redundant ARIA.

Bad:

<button role="button">

---

Navigation

Provide a skip link.

Example:

<a href="#main" class="skip-link">
  Skip to main content
</a>

Use landmarks:

<header>
<nav>
<main id="main">
<footer>

---

Tables

Use proper table structure.

Good:

<table>
  <thead>
    <tr>
      <th scope="col">Name</th>
      <th scope="col">Role</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Alice</td>
      <td>Admin</td>
    </tr>
  </tbody>
</table>

Avoid tables for layout.

---

Dialogs

Requirements:

• focus trap
• Escape closes dialog
• initial focus
• restore focus afterward

Angular Material Dialog already supports most of these.

Add:

<h2 mat-dialog-title>

for proper dialog labeling.

---

Custom Components

When creating custom controls:

Implement:

• keyboard interaction
• focus visibility
• accessible name
• appropriate ARIA state

Example checklist:

• Tab reachable
• Enter works
• Space works
• Focus visible
• Screen reader announces purpose

---

Color and Contrast

Minimum ratios:

Text	Ratio
Normal	4.5:1
Large	3:1

Never communicate information using color alone.

Instead of:

• Red = error

Use:

• icon
• text
• color

---

Focus Indicators

Never remove focus outlines unless replacing them.

Good:

:focus-visible {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

Avoid:

outline: none;

---

Motion

Respect reduced motion.

Example:

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none;
    transition: none;
  }
}

---

Angular Material Guidance

Prefer built-in accessible components.

Good choices:

• MatButton
• MatDialog
• MatMenu
• MatCheckbox
• MatRadio
• MatSelect
• MatSnackBar
• MatTabs

Verify:

• labels
• keyboard support
• announcements

---

Testing Checklist

Before completing any accessibility task:

Keyboard

• Everything reachable with Tab
• No keyboard traps
• Enter works
• Space works
• Escape works where appropriate

Screen Reader

• Controls have accessible names
• Form fields have labels
• Errors are announced
• Dynamic updates are announced

Visual

• Contrast passes WCAG
• Focus visible
• No color-only communication
• Text scales properly

---

Automated Testing

Recommend these tools:

Angular ESLint

Enable accessibility rules.

axe-core

Use for automated audits.

Example:

• axe DevTools
• Cypress + axe
• Playwright + axe

Lighthouse

Run accessibility audits regularly.

Treat Lighthouse as a guide rather than the only authority.

---

Code Review Rules

Whenever reviewing Angular code:

1. Replace non-semantic elements with semantic HTML.
2. Add missing labels.
3. Improve keyboard support.
4. Remove unnecessary ARIA.
5. Fix focus management.
6. Ensure dynamic updates are announced.
7. Verify Angular Material accessibility.
8. Confirm WCAG 2.2 AA compliance.

Always explain:

• why the issue affects accessibility
• the WCAG principle involved
• the preferred Angular solution
• the corrected code