Components · Form Controls
Slider
Lets people pick a value from a range by dragging.
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Slider · Canonical Spec
<div class="as-slider-field">
<div class="as-slider-field__header">
<label class="as-slider-field__label" for="mem-slider">Memory Limit</label>
<span class="as-slider-field__value">75%</span>
</div>
<div class="as-slider-box">
<input type="range" class="as-slider" id="mem-slider" min="10" max="100" value="75">
</div>
</div># Aster Component Implementation Prompt — Slider
## 1. Component Purpose & Canonical Role
- **Component:** Slider (`slider`)
- **Category:** Form Controls
- **Native Element:** `<input type="range">`
- **Summary:** Lets people pick a value from a range by dragging.
- **When to Use:** Resource thresholds, capacity percentages, audio/display levels.
- **When Not to Use:** Exact arbitrary numbers where typing is faster (use Input type="number").
## 2. Authoritative Repository Files
- **Component CSS:** `components/slider/slider.css`
- **Component Spec:** `docs/components/slider.md`
- **Agent Contract:** `skills/using-aster-components/SKILL.md`
- **Compiled Bundle:** `dist/css/aster.css` and `dist/js/aster.js`
## 3. Canonical HTML Structure & Classes
```html
<div class="as-slider-field">
<div class="as-slider-field__header">
<label class="as-slider-field__label" for="mem-slider">Memory Limit</label>
<span class="as-slider-field__value">75%</span>
</div>
<div class="as-slider-box">
<input type="range" class="as-slider" id="mem-slider" min="10" max="100" value="75">
</div>
</div>
```
## 4. Measured Geometry
Measured from the rendered component when this page loads.
## 5. Non-Negotiable Aster Constraints
1. **Zero Primitive Color Leaks:** Bind colors strictly to `--as-semantic-color-*` custom properties. Never use `--as-color-primitive-*` or hardcoded hex values in component usage.
2. **Minimum 4px Radius Policy:** Never use `2px` border-radius. Use `--as-radius-sm` (`4px`), `--as-radius-md` (`8px`), `--as-radius-lg` (`12px`), or `--as-radius-full` (`9999px`).
3. **Single Standard Density Mode:** Compact mode (`data-density="compact"` / `.as-*--compact`) is permanently retired. Do not emit compact classes or attributes.
4. **WCAG 2.2 AA Accessibility:** Maintain >= 4.5:1 text contrast, >= 3:1 UI/border contrast, >= 24x24px interactive hit targets, and full keyboard operability (`Tab`, `Enter`, `Space`, `Escape`, Arrow keys).
## 6. Verification Commands
```bash
npm run test:components
npm run test:contrast
npm run test:browser
``` When to use it
Do
- Use it when the rough position matters more than the exact number.
- Show the current value beside it.
Don't
- Use it when an exact number matters. Use Input instead.
- Use it for a huge range with tiny steps.
Variants & States
Every option, rendered live with real styles.
Accessibility & Keyboard Interaction
Requirements for using this component accessibly, following the W3C ARIA Authoring Practices Guide.
| Interaction / Key | Behavior & Compliance Requirement |
|---|---|
| Arrow Keys | Increments or decrements by step value. |
| Home / End | Jumps to min or max bound. |
Tokens
Values update with the current theme.
| Role | Token | Current value |
|---|---|---|
| Filled Track | --as-semantic-color-interactive-primary | |
| Unfilled Track | --as-semantic-color-surface-muted |