Dice UI

Installation

CLI

npx shadcn@latest add "https://diceui.com/r/composition"

Manual

Copy and paste the following code into your project.

import * as React from "react";
 
/**
 * A utility to compose multiple event handlers into a single event handler.
 * Call originalEventHandler first, then ourEventHandler unless prevented.
 */
function composeEventHandlers<E>(
  originalEventHandler?: (event: E) => void,
  ourEventHandler?: (event: E) => void,
  { checkForDefaultPrevented = true } = {},
) {
  return function handleEvent(event: E) {
    originalEventHandler?.(event);
 
    if (
      checkForDefaultPrevented === false ||
      !(event as unknown as Event).defaultPrevented
    ) {
      return ourEventHandler?.(event);
    }
  };
}
 
/**
 * @see https://github.com/radix-ui/primitives/blob/main/packages/react/compose-refs/src/compose-refs.tsx
 */
 
type PossibleRef<T> = React.Ref<T> | undefined;
 
/**
 * Set a given ref to a given value.
 * This utility takes care of different types of refs: callback refs and RefObject(s).
 */
function setRef<T>(ref: PossibleRef<T>, value: T) {
  if (typeof ref === "function") {
    return ref(value);
  }
 
  if (ref !== null && ref !== undefined) {
    ref.current = value;
  }
}
 
/**
 * A utility to compose multiple refs together.
 * Accepts callback refs and RefObject(s).
 */
function composeRefs<T>(...refs: PossibleRef<T>[]): React.RefCallback<T> {
  return (node) => {
    let hasCleanup = false;
    const cleanups = refs.map((ref) => {
      const cleanup = setRef(ref, node);
      if (!hasCleanup && typeof cleanup === "function") {
        hasCleanup = true;
      }
      return cleanup;
    });
 
    // React <19 will log an error to the console if a callback ref returns a
    // value. We don't use ref cleanups internally so this will only happen if a
    // user's ref callback returns a value, which we only expect if they are
    // using the cleanup functionality added in React 19.
    if (hasCleanup) {
      return () => {
        for (let i = 0; i < cleanups.length; i++) {
          const cleanup = cleanups[i];
          if (typeof cleanup === "function") {
            cleanup();
          } else {
            setRef(refs[i], null);
          }
        }
      };
    }
  };
}
 
/**
 * A custom hook that composes multiple refs.
 * Accepts callback refs and RefObject(s).
 */
function useComposedRefs<T>(...refs: PossibleRef<T>[]): React.RefCallback<T> {
  // eslint-disable-next-line react-hooks/exhaustive-deps
  return React.useCallback(composeRefs(...refs), refs);
}
 
export { composeEventHandlers, composeRefs, useComposedRefs };

Usage

Composing Event Handlers

import { composeEventHandlers } from "@/lib/composition"
 
function Button({ onClick, ...props }) {
  const handleClick = composeEventHandlers(onClick, (event) => {
    console.log("Button clicked")
  })
 
  return <button onClick={handleClick} {...props} />
}

Composing Refs

import { useComposedRefs } from "@/lib/composition"
 
function Input({ forwardedRef, ...props }) {
  const localRef = React.useRef(null)
  const composedRefs = useComposedRefs(forwardedRef, localRef)
 
  return <input ref={composedRefs} {...props} />
}