How to add “refs” dynamically with react hooks?

by

Not sure i fully understand your intent, but i think you want something like this: 

const {
  useState,
  useRef,
  createRef,
  useEffect
} = React;

const data = [
  {
    text: "test1"
  },
  {
    text: "test2"
  }
];

const Component = () => {
  const [heights, setHeights] = useState([]);
  const elementsRef = useRef(data.map(() => createRef()));

  useEffect(() => {
    const nextHeights = elementsRef.current.map(
      ref => ref.current.getBoundingClientRect().height
    );
    setHeights(nextHeights);
  }, []);

  return (
    <div>
      {data.map((item, index) => (
        <div ref={elementsRef.current[index]} key={index} className={`item item-${index}`}>
          {`${item.text} - height(${heights[index]})`}
        </div>
      ))}
    </div>
  );
};

const rootElement = document.getElementById("root");
ReactDOM.render(<Component />, rootElement);
.item {
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid #ccc;
}

.item-0 {
  height: 25px;
}

.item-1 {
  height: 50px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.6/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.6/umd/react-dom.production.min.js"></script>
<div id="root"/>

More Related Contents:

  1. The useState set method is not reflecting a change immediately
  2. React Hook Warnings for async function in useEffect: useEffect function must return a cleanup function or nothing
  3. How can I use multiple refs for an array of elements with hooks?
  4. How can I use React hooks in React classic `class` component?
  5. Invalid hook call. Hooks can only be called inside of the body of a function component
  6. Can I set state inside a useEffect hook
  7. How to call an async function inside a UseEffect() in React?
  8. Why is useState not triggering re-render?
  9. “Cannot use import statement outside a module” error when importing react-hook-mousetrap in Next.js
  10. Where can I make API call with hooks in react?
  11. How to register event with useEffect hooks?
  12. Is there a generic way to set state in React Hooks? How to manage multiple states?
  13. React Function Components with hooks vs Class Components
  14. How can I force a component to re-render with hooks in React?
  15. React hooks: accessing up-to-date state from within a callback
  16. Executing async code on update of state with react-hooks
  17. React Hooks – What’s happening under the hood?
  18. Why React Hook useState uses const and not let
  19. How to change the value of a Context with useContext?
  20. How to prevent re-rendering of components that have not changed?
  21. How target DOM with react useRef in map
  22. React Hooks Error: Hooks can only be called inside the body of a function component
  23. Next.js context provider wrapping App component with page specific layout component giving undefined data
  24. React hooks: call component as function vs render as element
  25. React hooks useState setValue still rerender one more time when value is equal
  26. React hook useEffect runs continuously forever/infinite loop
  27. useMemo vs. useEffect + useState
  28. Equivalent to componentDidUpdate using React hooks
  29. Updating state to the same value directly in the component body during render causes infinite loop
  30. React Hooks render twice

Leave a Comment