React Form Validator

React Form Validator exposes a single React component which uses the render prop pattern to validate the input on its child form.
It is built as a pure React component, with no additional dependencies, making it efficient and cheap to add to any React project. Due to interacting with underlying basic HTML tags, it is compatible with popular design Frameworks like Semantic or Bootstrap out of the box.

Table of Contents

Installation

• 1.1 - Using NPM/YARN
• 1.2 - Clone the repo

Usage

• 2.1 - Example
• 2.2 - Props in RFVC
  • 2.2.1 - Required props
  • 2.2.2 - Optional props
• 2.3 - Rules in RFVC
  • 2.3.1 - Default rules
  • 2.3.2 - Custom rules
• 2.4 - Arguments in RFVC
• 2.5 - Other options
  • 2.5.1 - Group Validation

Project Motivation

Additional Info

• Current Goals
• Changelog
• License

Installation

NPM/YARN

yarn add react-form-validator-component

import { Validator } from 'react-form-validator-component'

Clone

git clone [email protected]:JDLT-Ltd/react-form-validator-component.git

react-form-validator-component comes with a usage example that can be viewed by cloning the repo and running yarn start

Usage

Example

class ExampleForm extends React.Component {
  constructor(props) {
    super(props)

    this.state = {
      fields: {
        emailAddress: {
        name: 'emailAddresses',
        rules: ['isEmailArray'],
        required: true,
        label: 'Email addresses'
        }
      }
    }
  }

  render() {
    return (
      <Validator fields={this.state.fields} parent={this}>
        {({ isFormValid, fields, onChange, errors }) => {
          return (
            <form>
              <label>Your Emails</label>
              <input name="emailAddresses" onChange={onChange} />
              {errors.emailAddresses.map((error, i) => {
                return <span key={i}>{error}</span>
              })}
              {isFormValid && <button type="submit">Submit</button>}
            </form>
          )
        }}
      </Validator>
    )
  }
}

Props in RFVC

Required props

Validator has two required props

• fields - an object with one property per input field
  The structure of a field object is as follows

  Required Keys

  • rules - Each object must have a rules array, containing any combination of strings referring to our predefined validation rules and user-defined custom rules.
  • name - The second required key is name which names the field you are validating. This must correspond to the name of the input field you want to validate.

  Optional Keys

  • required - This key determines whether a field is required. If is is set to true, the field will only pass validation with a value. It can alternatively be set to a string which names the validation group it is a part of. See Group Validation
  • defaultValue - You can optionally provide a defaultValue property for each field. This is only required if you want to validate your form on load but are using form field components which don't correlate one-to-one with actual DOM nodes.
  • onChange - You can pass a custom onChange for each field, in case you have certain fields which need to be handled differently from the default. E.g. semantic-ui-react's DropDown component (i.e. the matching name attribute cannot be found on a DOM node containing the value to be validated). In those cases, the Validator's default method of checking values on load will fail. However, validation on change will be unaffected.
  • label - You can provide a label key, which will be returned from Validator in case you want to map over fields in order to build a form.

• parent - a reference to the component whose state Validator should add validated form data to.
  RFVC requires the parent components this context for several operations. By default a property will be added to parent's state with a key equal to the name attribute of its input and a value equal to the validated input.

Optional Props

Validator also has three optional props

• onValidate - A handler defining what to do with validated input.
  By default, Validator will set parent.state[fieldName] to be either valid input or null if input is invalid.

• validateOnLoad - a boolean
  By default Validator will attempt to validate every field that is prepopulated on componentDidMount. (Empty required fields will not display errors - however they will set isFormValid to false).
  If you want to avoid validation running on load, simply set the value to false.

• returnInput - a boolean
  By default Validator will only affect the parent components state when an inputs validation state changes. That is, when input passes validation it is passed to the parents state and if it fails validation it is set to null.
  If you pass the returnInput prop, RFVC will always update an Object on the parent's state which contains a key for each input and the corresponding value.

Rules in RFVC

You can use a mixture of predefined rules and your personal custom rules, just as it let's you provide your own functionality for onPassValidation.

Default Rules

fields: {
  emailAddress: {
        name: 'emailAddresses',
        rules: ['isEmailArray'],
        required: true,
        label: 'Email addresses'
      }
}

We are currently still working on creating a comprehensive list of default rules, please check src/lib/rules.js for now.

Custom Rules

const fields = {
  emailAddress: { 
    name: 'emailAddresses',
    required: true,
    label: 'Email addresses',
    rules: [
      'isEmail',
      {
        validator: data => {
          if (data) return true
          return false
        },
        error: 'Please provide a value'
      }]
  }
}

You can write custom rules and simply use them inside the rules Array as long as they follow RFVC's format of

{
  validator: {Your Code},
  error: {Your Error Message}  
}

Where validator is a function returning a boolean and error is the desired error message.

Arguments

The following arguments are provided to the render prop function:

isFormValid

A boolean. true when all inputs are validated.

isFieldValid

An object with a property for each field. The key matches the name property of the field and the value will be true if that field is valid and false if it's not.

fields

An array of objects which can optionally be used in the render prop function to build your form using a map. Each object will contain within its value property all properties that were passed into Validator.

i.e.

const = fields: {
        emailAddress: {
          rules: ['isEmail', 'isRequired'],
          label: 'email address'
        }
      }

becomes

;[
  {
    key: 'emailAddress',
    value: {
      rules: ['isEmail', 'isRequired'],
      label: 'email address'
    }
  }
]

onChange

onChange will validate the input provided and then update the parent component's state, adding any valid input and removing possible invalid input.

errors

Validator will also provide an errors object, which contains a key for each validated input, the value of which is an array containing all applicable errors. These can be displayed as a group or be mapped in order to produce individual error labels.

Other Options

Group Validation

RFVC supports group validation, where only one member of a group needs to pass it's validation in order for the whole group to be validated.
In order to use group validation, simply replace the value of the required key on fields with the groupname.

i.e.

const fields = {
    emailAddresses: {
      name: 'emailAddresses',
      rules: ['isEmailArray'],
      required: 'test',
      label: 'Email addresses'
    },
    something: {
      name: 'something',
      rules: ['isPhoneNumber'],
      required: 'test',
      label: 'Something'
    }
}