@data-slot/collapsible

Headless collapsible (show/hide) component for vanilla JavaScript. Accessible, unstyled, tiny.

Installation

``bash
npm install @data-slot/collapsible
`

Quick Start

`html



`

API

$3

Auto-discover and bind all collapsible instances in a scope (defaults to document).

`typescript
import { create } from "@data-slot/collapsible";

const controllers = create(); // Returns CollapsibleController[]
`

$3

Create a controller for a specific element.

`typescript
import { createCollapsible } from "@data-slot/collapsible";

const collapsible = createCollapsible(element, {
defaultOpen: false,
onOpenChange: (open) => console.log(open),
});
`

$3

| Option | Type | Default | Description |
|--------|------|---------|-------------|
| defaultOpen | boolean | false | Initial open state |
| onOpenChange | (open: boolean) => void | undefined | Callback when open state changes (not called on init) |

$3

Options can also be set via data attributes on the root element. JS options take precedence.

| Attribute | Type | Default | Description |
|-----------|------|---------|-------------|
| data-default-open | boolean | false | Initial open state |

Boolean attributes: present or "true" = true, "false" = false, absent = default.

`html



| Method/Property | Description |
|-----------------|-------------|
| open() | Open the collapsible |
| close() | Close the collapsible |
| toggle() | Toggle the collapsible |
| isOpen | Current open state (readonly boolean) |
| destroy() | Cleanup all event listeners |

Markup Structure

`html


Both collapsible-trigger and collapsible-content are required.

Styling

Use data-state attributes for CSS styling (available on both root and content):

`css
/ Hidden state /
[data-slot="collapsible-content"][hidden] {
display: none;
}

/ Or use data-state /
[data-slot="collapsible"][data-state="closed"] [data-slot="collapsible-content"] {
display: none;
}

/ Animate using data-state on content /
[data-slot="collapsible-content"] {
overflow: hidden;
transition: max-height 0.3s;
max-height: 0;
}

[data-slot="collapsible-content"][data-state="open"] {
max-height: 500px;
}
`

With Tailwind:

`html


- aria-expanded state on trigger
- aria-controls linking trigger to content
- role="region" on content
- aria-labelledby linking content back to trigger
- Unique ID generation for trigger and content
- Disabled trigger support (respects disabled attribute and aria-disabled="true")

Events

$3

Listen for changes via custom events:

`javascript
element.addEventListener("collapsible:change", (e) => {
console.log("Collapsible open:", e.detail.open);
});
`

$3

Control the collapsible via events:

| Event | Detail | Description |
|-------|--------|-------------|
| collapsible:set | { open: boolean } | Set open state programmatically |

`javascript
// Open the collapsible
element.dispatchEvent(
new CustomEvent("collapsible:set", { detail: { open: true } })
);

// Close the collapsible
element.dispatchEvent(
new CustomEvent("collapsible:set", { detail: { open: false } })
);
`

Note: Blocked when trigger is disabled (has disabled attribute or aria-disabled="true").

#### Deprecated Shapes

The following shape is deprecated and will be removed in v1.0:

`javascript
// Deprecated: { value: boolean }
element.dispatchEvent(
new CustomEvent("collapsible:set", { detail: { value: true } })
);
`

Use { open: boolean }` instead.

License

MIT