useRef TypeScript – not assignable to type LegacyRef

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I am trying to use useRef with TypeScript but am having some trouble.

With my RefObject (I assume) I need to access current. (ie node.current)

I have tried the following

  • const node: RefObject<HTMLElement> = useRef(null);
  • const node = useRef<HTMLElement | null>(null);

but when I go to set the ref I am always told that X is not assignable to type 'LegacyRef<HTMLDivElement> | undefined'.

return <div ref={ node }>{ children }</div>

Edit: this should not be restricted to any one type of element so not just HTMLDivElement | HTMLFormElement | HTMLInputElement

Edit: This should work as an example

import React, { useRef, RefObject } from 'react';

function Test() 
{
    // const node = useRef(null);
    // const node: RefObject<HTMLElement> = useRef(null);
    const node = useRef<HTMLElement | null>(null);

    if (
        node &&
        node.current &&
        node.current.contains()
    ){ console.log("current accessed")}

    return <div ref={ node }></div>
}

Solution

Just import React:

import React, { useRef } from 'react';

function Test() {
    const node = useRef<HTMLDivElement>(null);

    if (
        node &&
        node.current &&
        node.current.contains()
    ){ console.log("current accessed")}

    return <div ref={node}></div>
}

I made an update. Use HTMLDivElement as generic parameter instead of HTMLElement | null. Also, contains expects an argument.

UPDATE
useRef expects generic argument of DOM element type. You don’t need to use | null because RefObject already knows that current might be null.

See next type:

interface RefObject<T> {
  readonly current: T | null
}

TS & React are smart enough to figure out that your ref might be null

Source: StackOverflow.com

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