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de-formed-validations

2.0.6 • Public • Published

De-Formed Validations

De-Formed Validations is a robust and unopinionated API to manage form and data validations in JavaScript and React. With only a handful of properties to learn, de-formed maintains its own internal state with simple function calls so that you can design your architecture the way you want to.

Why Use De-Formed?

  1. Modular and Composable
  2. Easier to learn than the effect of pissing into the wind
  3. Powerful enough to handle any level of complexity
  4. Works for Client or Server.

Install

yarn add de-formed-validations
npm install de-formed-validations

React Usage

Step 1: Create a file to define your validations.

// PersonValidation.ts
import { useValidation } from 'de-formed-validations';
 
export const PersonValidation = () => {
  return useValidation<Person>({
    firstName: [
      {
        errorMessage: 'First Name is required.',
        validation: (val: string) => val.length > 0,
      },
      {
        errorMessage: 'First Name cannot be longer than 20 characters.',
        validation: (val: string) => val.length <= 20,
      },
    ],
    lastName: [
      {
        errorMessage: 'Last Name is required.',
        validation: (val: string) => val.length > 0,
      },
      {
        errorMessage: 'Last Name cannot be longer than 20 characters.',
        validation: (val: string) => val.length <= 20,
      },
      {
        errorMessage: 'Must be Ross if fist name is Bob.',
        validation: (val: string, state: Person) => {
          return state.firstName === 'Bob' ? val === 'Ross' : true;
        },
      },
    ],
  });
};

Step 2: Plug into React Component

// PersonForm.component.tsx
import React from 'react';
import { PersonValidation } from './PersonValidation';
 
export const PersonForm = ({ person, onChange }) => {
  const v = PersonValidation();
 
  const handleChange = v.validateOnChange(onChange, person);
  const handleBlur = v.validateOnBlur(person);
 
  const handleSubmit = (e: any) => {
    e.preventDefault();
    const canSubmit = v.validateAll(person);
    if (canSubmit) {
      // submit logic
    }
  };
 
  return (
    <form onSubmit={handleSubmit}>
      <div>
        <label>First Name</label>
        <input
          name="firstName"
          onBlur={handleBlur}
          onChange={handleChange}
          value={person.firstName}
        />
        {v.getError('firstName') && <p>{v.getError('firstName')}</p>}
      </div>
      <div>
        <label>Last Name</label>
        <input
          name="lastName"
          onBlur={handleBlur}
          onChange={handleChange}
          value={person.lastName}
        />
        {v.getError('lastName') && <p>{v.getError('lastName')}</p>}
      </div>
      <button>Submit</button>
    </form>
  );
};

Node/Express or Vanilla JavaScript Usage

Step 1: Create a file to define your validations.

// PersonValidation.js
import { Validation } from 'de-formed-validations';
 
export const PersonValidation = () => {
  return new Validation({
    firstName: [
      {
        errorMessage: 'First Name is required.',
        validation: val => val.length > 0,
      },
      {
        errorMessage: 'First Name cannot be longer than 20 characters.',
        validation: val => val.length <= 20,
      },
    ],
    lastName: [
      {
        errorMessage: 'Last Name is required.',
        validation: val => val.length > 0,
      },
      {
        errorMessage: 'Last Name cannot be longer than 20 characters.',
        validation: val => val.length <= 20,
      },
      {
        errorMessage: 'Must be Ross if fist name is Bob.',
        validation: (val, person) => {
          return person.firstName === 'Bob' ? val === 'Ross' : true;
        },
      },
    ],
  });
};

Step 2: Import as needed

// controller.js
const PersonValidation = require('./PersonValidation');
 
app.use("/", (req, res) => {
  const v = PersonValidation();
  return v.validateAll(req.body)
    ? res.json('success')
    : res.json(v.validationState);
});

A Different Approach

De-formed generates validations by calling an array of functions that define the exact requirements for a given property. There are no special properties to define (e.g. type, length, max, min, etc). We avoided this because it creates assumptions about how validations are supposed to generate error messages and our goal is make validations that are as unopinionated as possible; therefore, each function returns either true or false, and if it fails, it generates the error message associated with that function.

Importantly, all validations are de-coupled from your form and controller architecture allowing them to be executed, reused, and composed together in any context necessary. Just define as many functions as you want in your schema and then execute them on whichever events you choose (client-side or server-side). This provides you with a function-based, modular approach to design validation patterns that meet your requirements without the hassle of managing the validation data yourself.

Documentation

Check out the documentation.

Examples

More examples and CodeSandboxes.

Coverage

test coverage

License

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

Install

npm i de-formed-validations

DownloadsWeekly Downloads

106

Version

2.0.6

License

MIT

Unpacked Size

128 kB

Total Files

38

Last publish

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