ReactJS and Typescript : refers to a value, but is being used as a type here (TS2749) ReactJS and Typescript : refers to a value, but is being used as a type here (TS2749) reactjs reactjs

ReactJS and Typescript : refers to a value, but is being used as a type here (TS2749)


Make sure you're on a .tsx file and not a .ts file


So I ran into this problem multiple times in my code before but only figured out the reason this was happening today.

TL;DR at the end for the actual answer to the question.

When you create a class in TypeScript, the name of that class refers to both the instance type and the Javascript class value. If you reference that class as a type, TypeScript detects that automatically as the instance type of that class. And if you reference that class in the runtime, it just uses it as in the Javascript meaning. And it's all good and dandy till now.

class MyClass {}let abc: MyClass; // ts recognizes as instance typeabc = new MyClass(); // completely fine, used here as the javascript value

However, the real problem is when you export the class from a module dynamically. When you export the class in some ways, TypeScript can only export the Javascript value of the class and does not export the type. So if you import it in another module and try to reference it as a type, you will get TS2749.

let intervariable = class MyClass{}export const MyClass = intervariable; // TypeScript does not export type here.
import {MyClass} from './myclass';let abc: MyClass; // TypeScript error TS2749

When this happens, especially if it is out of your control, my solution to get the instance type was simply to use InstanceType and typeof:

import {MyClass} from './myclass';let abc: InstanceType<typeof MyClass>; // no error// the rest...

The typeof operator gets you the class constructor type for a class value, and the InstanceType generic gets you the instance type that you want.

TL;DR:In your case you just have to write InstanceType<typeof TextField> instead of TextField.