@halfdomelabs/cmdk v0.4.0

⌘K

⌘K is a command menu React component that can also be used as an accessible combobox. You render items, it filters and sorts them automatically. ⌘K supports a fully composable API How?, so you can wrap items in other components or even as static JSX.

This is a fork of CMDK that better supports usage in an auto-complete box by allowing use of the command list to exist within a Portal as well as separating the label from the unique value of the item. It also updated code based off eslint/prettier.

Demo and examples: cmdk.paco.me

Install

npm install cmdk

Use

import { Command } from '@halfdomelabs/cmdk';

const CommandMenu = () => {
  return (
    <Command label="Command Menu">
      <Command.Input />
      <Command.List>
        <Command.Empty>No results found.</Command.Empty>

        <Command.Group heading="Letters">
          <Command.Item>a</Command.Item>
          <Command.Item>b</Command.Item>
          <Command.Separator />
          <Command.Item>c</Command.Item>
        </Command.Group>

        <Command.Item>Apple</Command.Item>
      </Command.List>
    </Command>
  );
};

## Parts and styling

All parts forward props, including `ref`, to an appropriate element. Each part has a specific data-attribute (starting with `cmdk-`) that can be used for styling.

### Command `[cmdk-root]`

Render this to show the command menu inline. Can be controlled with the `value` and `onValueChange` props.

> **Note**
>
> Values are always converted to lowercase and trimmed. Use `apple`, not `Apple`.

```tsx
const [value, setValue] = React.useState('apple');

return (
  <Command value={value} onValueChange={setValue}>
    <Command.Input />
    <Command.List>
      <Command.Item>Orange</Command.Item>
      <Command.Item>Apple</Command.Item>
    </Command.List>
  </Command>
);

You can provide a custom filter function that is called to rank each item. Both strings are normalized as lowercase and trimmed.

<Command
  filter={(value, search) => {
    if (value.includes(search)) return 1;
    return 0;
  }}
/>

Or disable filtering and sorting entirely:

<Command shouldFilter={false}>
  <Command.List>
    {filteredItems.map((item) => {
      return (
        <Command.Item key={item} value={item}>
          {item}
        </Command.Item>
      );
    })}
  </Command.List>
</Command>

You can make the arrow keys wrap around the list (when you reach the end, it goes back to the first item) by setting the loop prop:

<Command loop />

Input [cmdk-input]

All props are forwarded to the underlying input element. Can be controlled with the value and onValueChange props.

const [search, setSearch] = React.useState('');

return <Command.Input value={search} onValueChange={setSearch} />;

List [cmdk-list]

Contains items and groups. Animate height using the --cmdk-list-height CSS variable.

[cmdk-list] {
  min-height: 300px;
  height: var(--cmdk-list-height);
  max-height: 500px;
  transition: height 100ms ease;
}

To scroll item into view earlier near the edges of the viewport, use scroll-padding:

[cmdk-list] {
  scroll-padding-block-start: 8px;
  scroll-padding-block-end: 8px;
}

Item [cmdk-item] [data-disabled?] [data-selected?]

Item that becomes active on pointer enter. You should provide a unique value for each item, but it will be automatically inferred from the .textContent.

<Command.Item
  onSelect={(value) => console.log('Selected', value)}
  // Value is implicity "apple" because of the provided text content
>
  Apple
</Command.Item>

You can force an item to always render, regardless of filtering, by passing the forceMount prop.

Group [cmdk-group] [hidden?]

Groups items together with the given heading ([cmdk-group-heading]).

<Command.Group heading="Fruit">
  <Command.Item>Apple</Command.Item>
</Command.Group>

Groups will not unmount from the DOM, rather the hidden attribute is applied to hide it from view. This may be relevant in your styling.

You can force a group to always render, regardless of filtering, by passing the forceMount prop.

Separator [cmdk-separator]

Visible when the search query is empty or alwaysRender is true, hidden otherwise.

Empty [cmdk-empty]

Automatically renders when there are no results for the search query.

Loading [cmdk-loading]

You should conditionally render this with progress while loading asynchronous items.

const [loading, setLoading] = React.useState(false);

return (
  <Command.List>
    {loading && <Command.Loading>Hang on…</Command.Loading>}
  </Command.List>
);

useCommandState(state => state.selectedField)

Hook that composes useSyncExternalStore. Pass a function that returns a slice of the command menu state to re-render when that slice changes. This hook is provided for advanced use cases and should not be commonly used.

A good use case would be to render a more detailed empty state, like so:

const search = useCommandState((state) => state.search);
return <Command.Empty>No results found for "{search}".</Command.Empty>;

Examples

Code snippets for common use cases.

Nested items

Often selecting one item should navigate deeper, with a more refined set of items. For example selecting "Change theme…" should show new items "Dark theme" and "Light theme". We call these sets of items "pages", and they can be implemented with simple state:

const ref = React.useRef(null);
const [open, setOpen] = React.useState(false);
const [search, setSearch] = React.useState('');
const [pages, setPages] = React.useState([]);
const page = pages[pages.length - 1];

return (
  <Command
    onKeyDown={(e) => {
      // Escape goes to previous page
      // Backspace goes to previous page when search is empty
      if (e.key === 'Escape' || (e.key === 'Backspace' && !search)) {
        e.preventDefault();
        setPages((pages) => pages.slice(0, -1));
      }
    }}
  >
    <Command.Input value={search} onValueChange={setSearch} />
    <Command.List>
      {!page && (
        <>
          <Command.Item onSelect={() => setPages([...pages, 'projects'])}>
            Search projects…
          </Command.Item>
          <Command.Item onSelect={() => setPages([...pages, 'teams'])}>
            Join a team…
          </Command.Item>
        </>
      )}

      {page === 'projects' && (
        <>
          <Command.Item>Project A</Command.Item>
          <Command.Item>Project B</Command.Item>
        </>
      )}

      {page === 'teams' && (
        <>
          <Command.Item>Team 1</Command.Item>
          <Command.Item>Team 2</Command.Item>
        </>
      )}
    </Command.List>
  </Command>
);

Show sub-items when searching

If your items have nested sub-items that you only want to reveal when searching, render based on the search state:

const SubItem = (props) => {
  const search = useCommandState((state) => state.search);
  if (!search) return null;
  return <Command.Item {...props} />;
};

return (
  <Command>
    <Command.Input />
    <Command.List>
      <Command.Item>Change theme…</Command.Item>
      <SubItem>Change theme to dark</SubItem>
      <SubItem>Change theme to light</SubItem>
    </Command.List>
  </Command>
);

Asynchronous results

Render the items as they become available. Filtering and sorting will happen automatically.

const [loading, setLoading] = React.useState(false);
const [items, setItems] = React.useState([]);

React.useEffect(() => {
  async function getItems() {
    setLoading(true);
    const res = await api.get('/dictionary');
    setItems(res);
    setLoading(false);
  }

  getItems();
}, []);

return (
  <Command>
    <Command.Input />
    <Command.List>
      {loading && <Command.Loading>Fetching words…</Command.Loading>}
      {items.map((item) => {
        return (
          <Command.Item key={`word-${item}`} value={item}>
            {item}
          </Command.Item>
        );
      })}
    </Command.List>
  </Command>
);

Use inside Popover

We recommend using the Radix UI popover component.

$ npm install @radix-ui/react-popover

Render Command inside of the popover content:

import * as Popover from '@radix-ui/react-popover';

return (
  <Popover.Root>
    <Popover.Trigger>Toggle popover</Popover.Trigger>

    <Popover.Content>
      <Command>
        <Command.Input />
        <Command.List>
          <Command.Item>Apple</Command.Item>
        </Command.List>
      </Command>
    </Popover.Content>
  </Popover.Root>
);

Drop in stylesheets

You can find global stylesheets to drop in as a starting point for styling. See website/styles/cmdk for examples.

FAQ

Accessible? Yes. Labeling, aria attributes, and DOM ordering tested with Voice Over and Chrome DevTools.

Virtualization? No. Good performance up to 2,000-3,000 items, though. Read below to bring your own.

Filter/sort items manually? Yes. Pass shouldFilter={false} to Command. Better memory usage and performance. Bring your own virtualization this way.

React 18 safe? Yes, required. Uses React 18 hooks like useId and useSyncExternalStore.

Unstyled? Yes, use the listed CSS selectors.

Hydration mismatch? No, likely a bug in your code.

React strict mode safe? Yes. Open an issue if you notice an issue.

Weird/wrong behavior? Make sure your Command.Item has a key and unique value.

Concurrent mode safe? Maybe, but concurrent mode is not yet real. Uses risky approaches like manual DOM ordering.

React server component? No, it's a client component.

Listen for ⌘K automatically? No, do it yourself to have full control over keybind context.

React Native? No, and no plans to support it. If you build a React Native version, let us know and we'll link your repository here.

History

Written in 2019 by Paco (@pacocoursey) to see if a composable combobox API was possible. Used for the Vercel command menu and autocomplete by Rauno (@raunofreiberg) in 2020. Re-written independently in 2022 with a simpler and more performant approach. Ideas and help from Shu (@shuding_).

use-descendants was extracted from the 2019 version.