README

useForm(📋, ⚙️) ⇒ Reactive Form ⚛️

GitHub code size in bytes npm minified bundle size npm gzipped bundle size typescript

Reactive form management and input field validation hook

Create a form model, flag input fields as required or add a value validation function with custom error messages. useForm will validate the inputs as the user types, when there are no errors the form gets enabled for submission. On form submission, it executes a callback function the user provides.

Requirements:

📋 Form model with optional validation function.
⚙️ Function to run after form validation and submission.
⚛️ React functional component with a form.

Install

npm install reactjs-use-form

🧪 Tested using @testing-library/react-hooks.
🏗️ Built with Rollup and CRACO.

Usage

Steps:

create a form model:

import { FormModelType } from 'reactjs-use-form';

export const formModel: FormModelType = {
  currentPassphrase: {
    value: '',
    required: true,
  },
  newPassphrase: {
    value: '',
    required: true,
    validator: (newPassphrase, values) => {
      if (newPassphrase === values?.currentPassphrase) {
        return 'New password must be different from current password';
      } else if (newPassphrase.length <= 5) {
        return 'Password must be at least 6 characters long';
      } else if (newPassphrase !== values?.verifyPassphrase) {
        return 'Passwords do not match';
      } else return '';
    },
  },
  verifyPassphrase: {
    value: '',
    required: true,
    validator: (verifyPassphrase, values) => {
      return verifyPassphrase !== values?.newPassphrase ? 'Passwords do not match' : '';
    },
  },
};

prepare a submit callback function, for example: function handleSubmit() {...}.
use the form model with the callback function in useForm hook in a functional react component:

Plain JSX code example

import React from 'react';
import { useForm, ValuesType } from 'reactjs-use-form';
import { formModel } from './formModel';

const ChangePassphraseComponent = () => {
  const {
    values,
    errors,
    handleOnChange,
    handleOnSubmit,
    isDisabled,
    isSubmitted
  } = useForm(formModel, handleSubmit);

  const { currentPassphrase, newPassphrase, verifyPassphrase }: ValuesType = values;

  function handleSubmit() {
    // formSubmitCallback();
  }

  return (
    <form onSubmit={handleOnSubmit}>
      <div>
        <label>Current Passphrase</label>
        <input
          type="password"
          name="currentPassphrase"
          value={currentPassphrase}
          onChange={handleOnChange}
        />
        <span>{errors.currentPassphrase.message}</span>
      </div>
      <div>
        <label>New Passphrase</label>
        <input
          type="password"
          name="newPassphrase"
          value={newPassphrase}
          onChange={handleOnChange}
        />
        <span>{errors.newPassphrase.message}</span>
      </div>
      <div>
        <label>Verify Passphrase</label>
        <input
          type="password"
          name="verifyPassphrase"
          value={verifyPassphrase}
          onChange={handleOnChange}
        />
        <span>{errors.verifyPassphrase.message}</span>
      </div>
      <span>{isSubmitted ? 'Passphrase has been changed!' : null}</span>
      <button type="submit" size="sm" disabled={isDisabled}>
        <span>Submit</span>
      </button>
    </form>
  );
};

Material-UI code example

import React from 'react';
import { Button, FormControl, FormGroup, FormHelperText, FormLabel, TextField } from '@material-ui/core';
import { useForm, ValuesType } from 'reactjs-use-form';
import { formModel } from './formModel';

const ChangePassphraseComponent = () => {
  const {
    values,
    errors,
    handleOnChange,
    handleOnSubmit,
    isDisabled,
    isSubmitted
  } = useForm(formModel, handleSubmit);

  const { currentPassphrase, newPassphrase, verifyPassphrase }: ValuesType = values;

  function handleSubmit() {
    // formSubmitCallback();
  }

  return (
    <form onSubmit={handleOnSubmit}>
      <FormGroup>
        <FormControl>
          <TextField
            required={true}
            label='Current Passphrase'
            type='password'
            name='currentPassphrase'
            error={errors.currentPassphrase.hasError}
            value={currentPassphrase}
            onChange={handleOnChange} />
          <FormHelperText error={errors.currentPassphrase.hasError}>
            {errors.currentPassphrase.message}
          </FormHelperText>
        </FormControl>
      </FormGroup>
      <FormGroup>
        <FormControl>
          <TextField
            required={true}
            label='New Passphrase'
            type='password'
            name='newPassphrase'
            error={errors.newPassphrase.hasError}
            value={newPassphrase}
            onChange={handleOnChange} />
          <FormHelperText error={errors.newPassphrase.hasError}>
            {errors.newPassphrase.message}
          </FormHelperText>
        </FormControl>
      </FormGroup>
      <FormGroup>
        <FormControl>
          <TextField
            required={true}
            label='Verify Passphrase'
            type='password'
            name='verifyPassphrase'
            error={errors.verifyPassphrase.hasError}
            value={verifyPassphrase}
            onChange={handleOnChange} />
          <FormHelperText error={errors.verifyPassphrase.hasError}>
            {errors.verifyPassphrase.message}
          </FormHelperText>
        </FormControl>
      </FormGroup>
      {isSubmitted ? <Alert variant='standard' severity='success' action='Passphrase has been changed!' /> : null}
      <Button type='submit' disabled={isDisabled}>
        Submit
      </Button>
    </form>
  );
};

Options

useForm takes two params: formModel and formSubmitCallback, returns the rest.

const {
  values,
  errors,
  handleOnChange,
  handleOnSubmit,
  isDisabled,
  isSubmitted
} = useForm(formModel, formSubmitCallback);

Param	Type	Description
values	`ValuesType`	returns form values state object
errors	`ErrorsType`	returns form errors state object
handleOnChange	`HandleOnChangeType`	binds to a `HTMLInputElement: change event`
handleOnSubmit	`HandleOnSubmitType`	binds to a `HTMLFormElement: submit event`
isDisabled	`boolean`	returns `true` / `false` when the form is valid / invalid
isSubmitted	`boolean`	returns `true` when the form was submitted without errors
formModel	`FormModelType`	initial form model with optional validation function
formSubmitCallback	`() => void`	function to run after form validation and submission

Type definitions: docs/definitions.md

License

GitHub

Usage no npm install needed!