Fully customisable react form utility.

🌈 Features

• Typescript compatible
• Customizable extractor, validator, getter and setters. (More in the docs)
• 0 Dependencies
• Tiny
• React Hooks

Links

• Live Web
• Live React-Native
• Examples
• Docs
  • Contructor
    • Initial State
    • Validators
    • Options
  • Returns
    • auto
    • form
    • errors
    • isValid
    • update

Installation

npm i formhero

🚀 Quickstart

import ReactDOM from 'react-dom'
import { useForm } from 'formhero'

const Form = () => {

  const { auto, form } = useForm({
    username: '',
    password: '',
  })

  const _submit = (e: React.FormEvent) => {
    e.preventDefault()
    console.log(form)
  }

  return (
    <div>
      <form onSubmit={_submit}>
        
        <input {...auto('username')} />
        <input {...auto('password')} />

        <button type="submit">Go 🚀</button>
      </form>
    </div>
  )
}

🔥 Examples

Validation

const Form = () => {

  const { auto, form, errors } = useForm({
    username: '',
    email: '',
    password: ''
  }, {
    username: value => value.length > 3,
    email: {
      validator: /@/,
      message: 'Must contain an @',
    },
    password: [
      {
        validator: /[A-Z]/,
        message: 'Must contain an uppercase letter'
      },
      {
        validator: /[\d]/,
        message: 'Must contain a digit'
      },
    ]
  })

  return (
    <form>

      <h1>Errors & Validation</h1>

      <input {...auto('username')} placeholder="Username" />
      {errors.username && 'Must be longer than 3'}

      <input {...auto('email')} placeholder="EMail" />
      {errors.email}

      <input {...auto('password')} placeholder="Password" type="password" />
      {errors.password}

    </form>
  )
}

Easy Customization

Often it happens that you use a specific input or framework, so the default getter, setter and extractor for the event won't cut it. No worries: formhero got you covered!

const Form = () => {

  const { auto, form, errors } = useForm({
    awesome: true,
  })

  return (
    <form onSubmit={e => {
      e.preventDefault()
      console.log(form)
    }}>

      <h1>Custom</h1>

      <label>
        <input type="checkbox" {...auto('awesome', {
          setter: 'checked',
          getter: 'onChange',
          extractor: (e) => e.target.checked
        })} />
        Is it awesome?
          </label>

      <input type="submit" />

    </form>
  )
}

📖 Documentation

useForm

const {auto, errors, update, form, isValid} = useForm(initial, validators, options)

Initial

This is the base state of the form. Also the typescript types are inhered by this.

Example

const initial = {
  username: 'defaultValue',
  password: '',
  rememberMe: true,
}

Validators

A validator is an object that taked in either a RegExp or a Function (can be async). Optionally you can pass a message string that will be displayed instead of the default one.

Example: Regular Expression

const validators = {
  // Only contains letters. 
  // This could also be a (also async) function that returns a boolean.
  username: /^[A-z]*$/,
}

Example: Function

const validators = {
  username: (value: string) => value.lenght > 3,
}

Example: With Object

const validators = {
  username: {
    validator: /^[A-z]*$/,
    message: 'My custom error message',
  }
}

Example: Multiple Validators

const validators = {
  username: [
    {
      validator: /^[A-z]*$/,
      message: 'My custom error message',
    },
    /[\d]/,
    async (value) => value.length > 0,
    {
      validator: (value) => true,
      message: 'Some other error',
    }
  ]
}

Options

Sometimes it's practical to have some different default values when using for example react-native or some other framework where the default value, onChange and (e)=> e.target.value do not apply.

Example: React Native (Method 1 - Global options)

Check the Expo Snack for a live preview

import * as React from 'react';
import { Text, SafeAreaView, TextInput } from 'react-native';
import { useForm } from 'formhero';

const initial = {
  username: 'i am all lowercase',
};
const validators = {};
const options = {
  setter: 'value', // This is not stricly necessarry as 'value' would already be the default.
  getter: 'onChangeText',
  extractor: text => text.toLowerCase(),
};

export default () => {
  const { form, auto } = useForm(initial, validators, options);

  return (
    <SafeAreaView>
      <TextInput
        style={{ height: 40, borderColor: 'gray', borderWidth: 2 }}
        {...auto('username')}
      />
      <Text>{form.username}</Text>
    </SafeAreaView>
  );
};

Example: React Native (Method 2 - Local overwrite)

// ...

export default () => {
  const { form, auto } = useForm({
    username: 'i am all lowercase',
  });

  return (
    <SafeAreaView>
      <TextInput
        style={{ height: 40, borderColor: 'gray', borderWidth: 2 }}
        {...auto('username', {
          setter: 'value', // This is not stricly necessarry as 'value' would already be the default.
          getter: 'onChangeText',
          extractor: text => text.toLowerCase(),
        })}
      />
      <Text>{form.username}</Text>
    </SafeAreaView>
  );
};