ReasonReact refs in stateless component

MyComponent.re

let component = ReasonReact.statelessComponent("MyComponent");

/**
 * This will be used to hold a ref to our input element
 */
let inputRef: ref(option('a)) = ref(None);

/**
 * sets the ref to the input element
 */
let setInputRef = theRef => inputRef := Js.Nullable.toOption(theRef);

/**
* Extracts a value from a DOM element and calls a provided function
*/
let handleSubmit = (_e, onSubmit) =>
  switch (inputRef^) {
  | Some((element: Dom.element)) =>
    onSubmit(ReactDOMRe.domElementToObj(element)##value)
  | _ => ()
  };

let make = (~onSubmit, _children) => {
  ...component,
  render: _self =>
    <div>
      <input ref=setInputRef _type="text" name="myinput" />
      <button onClick=(_e => handleSubmit(_e, onSubmit))>
        (ReasonReact.string("Submit"))
      </button>
    </div>,
};