useForm โ‡’ Reactive Form

Reactive form management and input field validation hook

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

Requirements:
  • ๐Ÿ“‹ Form model with optional validation function.
  • โš™๏ธ Function to run after form validation and submission.
  • โš›๏ธ React functional component with a form.

Install

npm install reactjs-use-form

Usage

Steps:
  1. create a form model:
import { FormModelType } from 'reactjs-use-form';

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' : '';
    },
  },
};
  1. use as a hook in a functional react component:
Plain JSX example code
import React from 'react';
import { useForm, ValuesType } from 'reactjs-use-form';

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

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

  function handleSave() {
    // 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}>
        Save Changes
      </Button>
    </form>
  );
};
Material-UI example code
import React from 'react';
import { Button, FormControl, FormGroup, FormHelperText, FormLabel, TextField } from '@material-ui/core';
import { useForm, ValuesType } from 'reactjs-use-form';

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

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

  function handleSave() {
    // 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}>
        <span>Save Changes</span>
      </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