Title rewritten to: "Invalid Hook call in react-hook-form"

Question

I'm new to react hook forms, so it might be a simple question. I just discovered that the Controller cannot use value as a number. This annoyed me a lot, but eventually I found the solution in github issue #8068, described as follows: Set up an onChange function, like this:

<Controller
- rules={{ valueAsNumber: true }}
      render={({ field }) => (
          <input
- onChange={field.onChange}
              onChange={(event) => field.onChange( event.target.value)}
              type="number"
          />
  )}
/>

So I modified it a little and got the following code:

import React, { ChangeEvent } from 'react'
import { Controller } from 'react-hook-form'
import { getPlaceholder } from './getPlaceholder'
import { IInput } from './types'

const NumberInput: React.FC<IInput> = ({ control, name, ...props }) => {
  const placeholder = getPlaceholder({ type: "number" });
  const numericalOnChange = (event: ChangeEvent<HTMLInputElement>) => {
    if (event.target.value === '') return null;
    return event.target.value;
  }

  return (
    <Controller
      control={control}
      name={name}
      render={({ field: { onChange, ...field } }) => (
        <input
          {...props}
          {...field}
          type="number"
          placeholder={placeholder}
          onChange={(event) => {
            const value = numericalOnChange(event)
            onChange(value)
          }}
          className="h-[20px] pl-[4px] py-[8px] bg-transparent border-b
          border-b-[#646464] focus:border-b-[#3898EC] text-[13px]
          text-[#F00] placeholder-[#646464] outline-none m-1 w-full"
        />
      )}
    />
  )
}

export default NumberInput

This should work in theory, but in practice will give an Invalid Hook Call Error.

Answer 1

Define the NumberInput component separately, and then use Controller packaging directly in the form:

// NumberInput.js
export const NumberInput = ({ value, onChange, ...rest }) => {
  const handleChange = (e) => {
    onChange(Number(e.target.value));
  };
 
  return (
    <input
      type="number"
      min={0}
      onChange={handleChange}
      value={value}
      {...rest}
    />
  );
};

Then within the component that calls useForm:

<Controller
  name='number'
  control={control}
  render={({ field: { ref, ...field } }) => (
    <NumberInput {...field} type="number" />
  )}
/>

You can find more information in this article.