useCollapsible

Usage#

import { useCollapsible } from '@primereact/headless/collapsible';

const { rootProps, triggerProps, contentProps, state } = useCollapsible();
 
<div {...rootProps}>
    <button {...triggerProps}></button>
    {state.open && <div {...contentProps}></div>}
</div>;

useCollapsible manages open/close state with toggle, open, and close methods — see Primitive for a component-based API.

Features#

• Open/close state machine — tracks a single boolean with matching aria-expanded, aria-controls, and data attributes
• Controlled or uncontrolled — use open/onOpenChange externally or rely on defaultOpen
• Imperative controls — toggle(), open(), and close() flip state from anywhere outside the trigger
• Lifecycle callbacks — onOpen and onClose fire alongside onOpenChange for per-direction side effects
• Primitive for other hooks — the building block that usePanel, useFieldset, and others wrap

Working with callbacks#

Controlled open state#

Drive open state from parent state with open and onOpenChange.

const [isOpen, setIsOpen] = React.useState(true);
 
const { state } = useCollapsible({
    open: isOpen,
    onOpenChange: (e) => setIsOpen(e.value)
});

Directional callbacks#

When you only care about one direction, use onOpen or onClose instead of branching inside onOpenChange.

useCollapsible({
    onOpen: () => analytics.track('panel_expanded'),
    onClose: () => analytics.track('panel_collapsed')
});

Imperative control from outside the trigger#

Expose toggle, open, and close on a ref or context so sibling UI can drive the panel.

const collapsible = useCollapsible({ defaultOpen: false });
 
<button onClick={(e) => collapsible.open(e)}>Expand</button>
<button onClick={(e) => collapsible.close(e)}>Collapse</button>

Composing into higher-level hooks#

useCollapsible is the primitive that higher-level hooks build on — wrap it to create your own collapsible surface with extra behavior.

function useDisclosurePanel(options) {
    const collapsible = useCollapsible(options);
    const [loaded, setLoaded] = React.useState(false);
 
    return {
        ...collapsible,
        loaded,
        onOpen: () => setLoaded(true) // load data the first time it opens
    };
}

Styling with data attributes#

The prop objects include data-scope="collapsible" and data-part. State is reflected via data-open/data-closed on root and content, and data-content-open/data-content-closed on the trigger.

[data-scope='collapsible'][data-part='root'][data-open] {
    border-color: var(--p-primary-color);
}
 
[data-scope='collapsible'][data-part='trigger'][data-content-open] svg {
    transform: rotate(180deg);
}

API#

useCollapsible#

Accessibility#

Enter or Space on the trigger toggles the content, and the trigger exposes aria-expanded state. See Primitive for full WAI-ARIA compliance details.