Supported number type for FormValue? about react-use-form-state HOT 5 CLOSED

Hi @hibado,

I think in your example above you meant to be using checkbox not a radio since the state is an array.

That said, numbers values in the form state are not currently support. Numeric values have to be strings.

This is because:

• the value attribute of a is and will always be a string (a DOMString)
• that makes it very tricky and not safe to assume that some values are going to be numbers.
• And even if they are numeric and I ended up parsing them to numbers, it might not be what users expect or want back. For example, a value may be an area code or a phone number "0011231234", or an id that starts with a 0.

To avoid confusion, this library, and many other form libraries, choose to work with strings. It's up to you if you want to cast such values to numbers.

Consider the following as a workaround to achieve what you want:

const Form = ({ onSubmit }) => {
  const [{ values }, { checkbox }] = useFormState<{ status: string[] }>({
    status: [0, 1, 2, 3].map(String),
  });

  const handleSubmit = e => {
    e.preventDefault();
    onSubmit({
      ...values,
      status: values.status.map(Number),
    });
  };

  return (
    <form onSubmit={handleSubmit}>
      {/* 
        as a convenience, you could still pass a number as a value (it'd be silly to
        have to cast to a number for each input, so keep in mind these values will 
        be returned as strings in the form state
      */}
      <input {...checkbox('status', 0)} />
      <input {...checkbox('status', 1)} />
      <input {...checkbox('status', 2)} />
      <input {...checkbox('status', 3)} />
      <button>Submit</button>
    </form>
  );
};

In future releases I might consider revisiting this issue and casting values to numbers only if an initial state is provided.

Thanks! Don't hesitate to reach out for any more questions you have.

from react-use-form-state.

I'm actually trying to use raw() right now, and unfortunately it doesn't seem to work with TS for exactly this reason.

I'm specifically trying to use http://jquense.github.io/react-widgets/api/NumberPicker/ , which really does require a number as its value, and its onChange passes in just a number.

That results in this TS error:

This is particularly annoying given that the source data field is a number, and I defined my TS form state type as having this field as a number.

from react-use-form-state.

Yeah, I just tried something along the same lines and got this to behave:

// components/react-widgets.tsx
import React from 'react';
import RWDateTimePicker from 'react-widgets/lib/DateTimePicker';
import RWNumberPicker from 'react-widgets/lib/NumberPicker';

type RWDTProps = React.ComponentProps<typeof RWDateTimePicker>;
type DTProps = Omit<RWDTProps, 'value'> & {
  value?: Date | null;
};

export const DateTimePicker = ({ value, ...otherProps }: DTProps) => {
  return <RWDateTimePicker value={value as any} {...otherProps} />;
};

type RWNPProps = React.ComponentProps<typeof RWNumberPicker>;
type NPProps = Omit<RWNPProps, 'value' | 'onChange'> & {
  value?: number | string;
  onChange?: (value: number) => any;
};

const noop = () => {};

export const NumberPicker = ({ value, onChange = noop, ...otherProps }: NPProps) => {
  const innerOnChange = (value: number = 0) => {
    onChange(value);
  };

  return <RWNumberPicker value={value as any} onChange={innerOnChange} {...otherProps} />;
};


// pages/myPage.tsx
import { DateTimePicker, NumberPicker } from 'components/react-widgets';

interface MyFormState {
  a: number
}

const initialState : MyFormState = {
  a: 0
}

const MyPage = () => {
  const [formState, {raw}] = useFormState<MyFormState>(initialState);

  return <NumberPicker {...raw('a')} />
}

That both compiles, and runs correctly, and I can see the actual numbers being stored.

from react-use-form-state.

Another alternative could be the raw input :-)

      <Slider
            {...raw('borderRadius')}
            value={values.borderRadius || undefined}
            aria-labelledby="border-radius-changer"
            min={0}
            max={100}
            valueLabelDisplay="on"
          />

from react-use-form-state.

@markerikson Actually I had sort of the same thing! I just forgot to update the comment. What I did to overcome the issue was creating a custom component

interface FormSliderProps extends Omit<SliderProps, 'onChange'> {
  onChange: (number: number) => any
}
function FormSlider({ onChange, ...rest }: FormSliderProps) {
  const onInnerChange = (e: any, v: number | number[]) => {
    onChange(Number(v) || 0)
  }

  return <Slider {...rest} onChange={onInnerChange} />
}

from react-use-form-state.