NOTE: This was an expeiriment exporing hooks while hooks was still in aplha. I don't use this in any projects and I have no intention of maintianing this project.

react-form-stateful

react-form-stateful a full featured, extensible form component for react using react hooks

NOTE: this project requires the use of an alpha version of react to use.

Getting Started

npm install --save react-form-stateful

Examples

Basic Usage

import { FC } from 'react';
import { StatefulForm, SFInput, SFSelect, SFTextArea } from 'react-form-stateful';
import * as yup from 'yup';

const ValidationSchemeForm: FC = () => {
  return (
    <StatefulForm
      validationSchema={yup.object().shape({
        email: yup
          .string()
          .required('Email required')
          .email('Invalid email address'),
        desc: yup.string().max(256, 'Please keep your description short!'),
        complaint: yup
          .string()
          .required('Complaint required')
          .max(10000, 'Max complaint size: 10,000 characters.'),
      })}
    >
      <div>Feedback form:</div>
      <label>
        Email:
        <SFInput name="email" />
      </label>
      <label>
        Short Description:
        <SFInput name="desc" />
      </label>
      <label>
        Reason for complaint:
        <SFSelect
          name="reason"
          defaultEntry={'Please select a reason'}
          values={['Bug', 'Typo', 'Feature Request', 'Other']}
        />
      </label>
      <label>
        Complaint:
        <SFTextArea name="complaint" />
      </label>
    </StatefulForm>
  );
};

Other examples

Other examples can be seen in the examples folder. ValidationScheme.tsx is a simple form and the other two are more complex.

Customizing Forms

Context is used to expose the state. This allows for helper hooks to be written. Several already exist, but more could easily be written. (Feel free to make a PR).

Components

One of the components from components:

type SFControlProps<T = string> = {
  name: string;
  className?: string;
  errorClassName?: string;
  initialValue?: T;
  defaultValue?: T;
};

export const SFInput: FC<SFControlProps> = props => {
  const { touch, value, setValue, error } = useSFControl(props.name, props.initialValue, props.defaultValue);
  return (
    <Fragment>
      <input className={props.className} onBlur={touch} value={value || ''} onChange={e => setValue(e.target.value)} />
      <div className={props.errorClassName}>{error}</div>
    </Fragment>
  );
};

Example Usage

import { FC, createElement } from 'react';
import { StatefulForm, SFInput } from 'react-form-stateful';

const Form: FC = () => {
  return (
    <StatefulForm>
      <SFInput name="item" />
    </StatefulForm>
  );
};

As you can see component that matches your application's look and feel, but basic components do exist for your convenience.

Extending

While the internal reducer is not exposed, the dispatch and actions are exposed, which allows for extension through side effects. An example of this can be seen in examples/pages/Pages.tsx.

NO_DEFAULT and ASYNC_VALIDATION

There are two special constants that help with extending the functionality of react-form-stateful.

NO_DEFAULT

NO_DEFAULT prevents resets from affecting this value. Useful for hidden from values that are used to control validation. This us used in the advanced example examples/pages/Pages:

const valueState = useSFValue<number[]>(
  '@@pages',
  [0],
  NO_DEFAULT, // Don't get reset
  value => (props.pages.length !== value.length ? 'more pages exist' : null)
);

ASYNC_VALIDATION

ASYNC_VALIDATION Is used to to defer the validation to some external process. This is useful when you want to defer the validation to a separate process. This could also be done with Promises, but there may be cases where ASYNC_VALIDATION is more convenient.

const { error, setValue, value, touch, touched } = useSFControl<string>(props.name, '', '', () => ASYNC_VALIDATION);

Here when a validation is triggered, the error state is set to { async:true }. The form is not submitable until this is resolved. One way to resolve this is to use the useSFError hook and set the error state for the component.

const [, setError] = useSFError(props.name);
setError('Invalid username');

Prior art

• Formik (Obviously)