Very simple usage of https://github.com/scoville/rescript-hook-form/

Form.res

module Form = {
  @react.component
  let make = () => {
    let {clearErrors, control, formState: {errors}, handleSubmit} = Hooks.Form.use(
      ~option=Hooks.Form.option(
        ~mode=#onBlur,
        ~shouldFocusError=false,
        ~defaultValues=Js.Dict.fromArray([(Values.title, Value.make(""))]),
        (),
      ),
      (),
    )

    let onSubmit = (data, _event) =>
      switch data->ReCode.Decode.decodeJson(Values.decoder) {
      | Ok(value) => Js.log2("ok", value)
      | Error(error) => Js.log2("ko", error)
      }

    <form onSubmit={handleSubmit(. onSubmit)}>
      <Controller
        name=Values.title
        control
        rules={Rules.make(~required=true, ())}
        render={({field: {name, onBlur, onChange, ref, value}}) =>
          <div>
            <label> {name->React.string} </label>
            <input name onBlur onChange onFocus={_event => clearErrors(. Values.title)} ref value />
            <ErrorMessage errors name message={"Required"->React.string} />
          </div>}
      />
      <input type_="submit" />
    </form>
  }
}

Values.res

open ReCode.Decode
open ReCode.DecodeExtra

type t = {title: string}

let title = "title"

let make = title => {title: title}

let decoder = pure(make)->Object.required(title, string->String.min(1))