Function cloneWithRef

packages/react-dnd/src/utils/cloneWithRef.js:4–29

(element, newRef)

import { cloneElement } from 'react';

export default function cloneWithRef(element, newRef) {
  const previousRef = element.ref;
  invariant(
    typeof previousRef !== 'string',
    'Cannot connect React DnD to an element with an existing string ref. ' +
    'Please convert it to use a callback ref instead, or wrap it into a <span> or <div>. ' +
    'Read more: https://facebook.github.io/react/docs/more-about-refs.html#the-ref-callback-attribute',
  );

  if (!previousRef) {
    // When there is no ref on the element, use the new ref directly
    return cloneElement(element, {
      ref: newRef,
    });
  }

  return cloneElement(element, {
    ref: (node) => {
      newRef(node);

      if (previousRef) {
        previousRef(node);
      }
    },
  });
}