Pristine - Vanilla javascript form validation library

~4kb minified, ~2kb gzipped, no dependencies

Living demo

Some examples of use can be found here.

Usage

Include the javascript file in your html head or just before the closing body tag

<script src="dist/pristine.js"  type="text/javascript"></script>

Now create some form and validate

window.onload = function () {

    var form = document.getElementById("form1");

    // create the pristine instance
    var pristine = new Pristine(form);

    form.addEventListener('submit', function (e) {
       e.preventDefault();
       
       // check if the form is valid
       var valid = pristine.validate(); // returns true or false

    });
};

That’s it

It automatically validates required, min, max, minlength, maxlength attributes and the value of type attributes like email, number and more..

Pristine takes 3 parameters

• form The form element

• config An object containing the configuration. Default is bootstrap’s configuration which is

let defaultConfig = {
    // class of the parent element where the error/success class is added
    classTo: 'form-group',
    errorClass: 'has-danger',
    successClass: 'has-success',
    // class of the parent element where error text element is appended
    errorTextParent: 'form-group',
    // type of element to create for the error text
    errorTextTag: 'div',
    // class of the error text element
    errorTextClass: 'text-help' 
};

• live A boolean value indicating whether pristine should validate as you type, default is true

Install

$ npm install pristinejs --save

Custom Validator

pristine.addValidator(nameOrElem, handler, errorMessage, priority, halt);

Add a custom validator to a field

var pristine = new Pristine(document.getElementById("form1"));

var elem = document.getElementById("email");

// A validator to check if the first letter is capitalized
pristine.addValidator(elem, function(value) {
    // here `this` refers to the respective input element
    if (value.length && value[0] === value[0].toUpperCase()){
        return true;
    }
    return false;
}, "The first character must be capitalized", 2, false);

Add a global custom validator

// A validator to check if the input value is within a specified range
// Global validators must be added before creating the pristine instance

Pristine.addValidator("my-range", function(value, param1, param2) {
    // here `this` refers to the respective input element
    return parseInt(param1) <= value && value <= parseInt(param2)
    
}, "The value (${0}) must be between ${1} and ${2}", 5, false);

Now you can assign it to your inputs like this

<input type="text" class="form-control" data-pristine-my-range="10,30" />

Add custom error messages

<input required data-pristine-required-message="My custom message"/>

Add an attribute like data-pristine-<ValidatorName>-messagewith the custom message as value to show custom error messages. You can add custom messages like this for as many validators as you need. Here ValidatorName means required, email, min, max etc.

Built-in validators

API

Pristine(form, config, live)
Constructor

pristine.validate(inputs, silent)
Validate the form or field(s)

pristine.addValidator(elem, fn, msg, priority, halt)
Add a custom validator

Pristine.addValidator(name, fn, msg, priority, halt)
Add a global custom validator

pristine.getErrors(input)
Get the errors of the form or a specific field

pristine.addError(input, error)
Add A custom error to an input element

pristine.setGlobalConfig(config)
Set the global configuration

Pristine.setLocale(locale)
Set the current locale globally

Pristine.addMessages(locale, messages)
Set the current locale globally

pristine.reset()
Reset the errors in the form

pristine.destroy()
Destroy the pristine object

The goal of this library is not to provide every possible type of validation and thus becoming a bloat. The goal is to provide most common types of validations and a neat way to add custom validators.

License

MIT