@de-formed/react-validations

What is De-Formed?

De-Formed is a library for designing modular, event-driven form and data validations. Bind the things you need; ignore the things you don't. De-Formed will take care of the rest so that you can design your architecture the way you want to.

Why Use De-Formed?

1. Modular - decoupled from your form architecture.
2. Composable - turn your validations and forms into Lego bricks.
3. Extendable - add/modify the API as you see fit
4. Unopinionated - customize your UX to the Moon 🚀
5. Lightweight - compare it on bundlephobia
6. Easy to Use - its all functions
7. Easy to Test - unit test your business logic
8. Yup Compatible - can integrate with your existing yup schemas

Install

yarn add @de-formed/react-validations

npm i @de-formed/react-validations

Basic Usage

Step 1: Define a hook/schema for your validations

// usePersonValidation.ts
import { useValidation } from '@de-formed/react-validations';

export const usePersonValidation = () => {
  return useValidation<Person>({
    firstName: [
      {
        error: 'First Name is required.',
        validation: ({ firstName }) => firstName.length > 0,
      },
    ],
    lastName: [
      {
        error: 'Last Name is required.',
        validation: ({ lastName }) => lastName.length > 0,
      },
    ],
  });
};

---

Step 2: Use the hook anywhere.

Bind the things you need; ignore the things you don't. De-Formed will take care of the rest.

// PersonForm.component.tsx
import React from 'react';
import { usePersonValidation } from './usePersonValidation';

export const PersonForm = ({ person, onChange }) => {
  const {
    getError,
    validateAll,
    validateOnChange,
    validateOnBlur
  } = usePersonValidation();

  const handleSubmit = () => {
    if (validateAll(person) {
      // submit logic
    }
  };

  return (
    <>
      <div>
        <label>First Name</label>
        <input
          name="firstName"
          onBlur={validateOnBlur(person)}
          onChange={validateOnChange(onChange, person)}
          value={person.firstName}
        />
        {getError('firstName') && <p>{getError('firstName')}</p>}
      </div>
      <div>
        <label>Last Name</label>
        <input
          name="lastName"
          onBlur={validateOnBlur(person)}
          onChange={validateOnChange(onChange, person)}
          value={person.lastName}
        />
        {getError('lastName') && <p>{getError('lastName')}</p>}
      </div>
      <button onClick={handleSubmit}>Submit</button>
    </>
  );
};

---

Validation Schema

The validation schema is on object that defines a list of validation rules for any given key. Each validation rule consists of the error to display to a user and a function that returns true or false. Error messages can be passed a function to generate dynamic error messages depending on the state of the data. Keys that match the keys of an object will be automatically detected when using validateAll.

{
  email: [
    {
      error: 'Email is required.',
      validation: ({ email }) => email.trim().length > 0,
    },
    {
    error: ({ email }) => `${email} must be a valid email.`,
      validation: ({ email, name }) =>
        name === 'bob ross' ? email === '[e-mail]' : true
    },
  ],
}

---

Auto-Props

Auto-props are functions that apply simple validation rules for strings and numbers.

type Person = {
  name: string
  age: number
  agreement: boolean
}

const personValidation = () => {
  return Validation<Person>({
    name: [required(), shorterThan(12)],
    age: [min(42), max(100)],
    agreement: [is(true, 'Must accept terms.')],
  })
}

---

Getting Started

Guided walkthrough of how to customize De-Formed to the moon 🚀

Documentation

API documentation.

Examples

More examples and CodeSandboxes.

License

This project is licensed under the terms of the MIT license.