Overview

Frontend form validation

Parsley is a javascript form validation library. It helps you provide your users with feedback on their form submission before sending it to your server. It saves you bandwidth, server load and it saves time for your users.

Javascript form validation is not necessary, and if used, it does not replace strong backend server validation.

That's why Parsley is here: to let you define your general form validation, implement it on the backend side, and simply port it frontend-side, with maximum respect to user experience best practices.

Data attributes

Parsley uses a specific DOM API which allows you to configure pretty much everything directly from your DOM, without writing a single javascript configuration line or custom function. Parsley's default DOM API is data-parsley-. That means that if in config you see a foo property, it can be set/modified via DOM with data-parsley-foo="value".

Configuration

You'll see along this documentation and through examples various available configuration options. You can also view here all of Parsley's default configuration options.

Installation

Basic installation

Parsley relies on jQuery (>= 1.8), and it will need to be included before including Parsley.

Then, you can either use parsley.js unminified file or parsley.min.js minified one. These files and other builds (Remote, Extras ..) are available here.

Finally, add data-parsley-validate to each <form> you want to be validated.

That would look pretty much like this:

<script src="jquery.js"></script>
<script src="parsley.min.js"></script>

<form data-parsley-validate>
...
</form>

Javascript installation

Like for Basic installation, first include jQuery and Parsley. Then, simply use $('#form').parsley(options); or new Parsley('#form', options); (where options is an optional configuration object) to manually bind Parsley to your forms.

That would look pretty much like this:

<script src="jquery.js"></script>
<script src="parsley.min.js"></script>

<form id="form">
...
</form>

<script type="text/javascript">
  $('#form').parsley();
</script>

Localization

Parsley comes with various error messages for its built-in validators. They are shipped in English by default, but many other languages are available, thanks to the awesome international Parsley community. See the available localizations here.

To load a different locale and its messages, you have two possibilities:

• Load your needed localization before Parsley, then select the one you need once Parsley is loaded and if you want to switch from the English default. In this example, we'll load both French and Italian translations, and use French:

  <script src="jquery.js"></script>
  <script src="i18n/fr.js"></script>
  <script src="i18n/it.js"></script>
  <script src="parsley.min.js"></script>
  <script type="text/javascript">
    window.ParsleyValidator.setLocale('fr');
  </script>
  

• Load your needed localization after Parsley. The last loaded file will automatically set the messages locale for ParsleyValidator. In this example, we'll load both French and Italian translations, and use Italian:

  <script src="jquery.js"></script>
  <script src="parsley.min.js"></script>
  <script src="i18n/fr.js"></script>
  <script src="i18n/it.js"></script>
  

Plugins

Parsley strives to be highly decoupled and modular. It uses events and inheritance, and allows various plugins.

Current available plugins are:

• Parsley Remote: provides an ajax validator and asynchronous validation
• Parsley Extras: provides some extras and useful validators

Usage

Overview

Parsley is a decoupled library that uses different classes to do the heavy work. You'll see here the different protagonists involved and how you can configure them to fit your desired validation.

Configuration

Data attributes and javascript

The multiple options can be specified using data attributes and javascript:

<input id="first" data-parsley-maxlength="42" value="hello"/>
<input id="second" value="world"/>
[...]
<script>
var instance = $('#first').parsley();
console.log(instance.isValid()); // maxlength is 42, so field is valid
$('#first').attr('data-parsley-maxlength', 4);
console.log(instance.isValid()); // No longer valid, as maxlength is 4
// You can access and override options in javascript too:
instance.options.maxlength++;
console.log(instance.isValid()); // Back to being valid, as maxlength is 5
// Alternatively, the options can be specified the first time a form/field is bound:
var otherInstance = $('#second').parsley({
  maxlength: 10
});
console.log(otherInstance.options); // Shows that maxlength will be 10 for this field

As shown in the previous example, Parsley will actualize the options from the data attributes whenever it needs to validate a field.

Option inheritance

Field instances inherit their options from Form instances, and both inherit from the global options. This is a handy way to configure all your form's inputs in a row by passing their config through form.

<form>
  <input/>
</form>
[...]
<script>
Parsley.options.maxlength = 42;
var formInstance = $('form').parsley();
var field = $('input').parsley();
console.log(field.options.maxlength); // Shows that maxlength is 42
Parsley.options.maxlength = 30;
console.log(field.options.maxlength); // Shows that maxlength is automagically 30
formInstance.options.maxlength++;
console.log(field.options.maxlength); // Shows that maxlength is automagically 31

The previous example shows that the inheritance of options is automagic. In case you are wondering, they are linked through prototype to achieve this.

Naming

You can change the DOM API namespace directly using the namespace option. Data attributes with compound names are camelcased for javascript, and their values are automatically converted to the appropriate type (boolean, integer, etc.). For example:

<input data-my-namespace-priority-enabled="false">
[...]
<script>
var instance = $('input').parsley({namespace: 'my-namespace-'});
if (false === instance.options.priorityEnabled)
  console.log("priorityEnabled was set to false");

Form

When doing $('#target').parsley() or new Parsley('#target'); on a <form id="target"> element, it will bind the whole form and its various inputs and return a ParsleyForm instance.

Options

data-parsley-excluded="input[type=button], input[type=submit], input[type=reset], input[type=hidden], [disabled], :hidden"

Methods

UI

Field

When doing $('#target').parsley() or new Parsley('#target'); on a <input id="target"> element (or <textarea>, <select>), it will bind the field and return a ParsleyField instance. Except for input types radio and checkbox that don't have a name attribute or a data-parsley-multiple attribute, they won't be bound (ignored) and will eventually raise a warning in the console.

Options

Methods

UI

Built-in validators

Overview

Parsley 2.x is now based on validator.js that ships commonly used validators and simplifies group and priority validation. That way, Parsley can share validators with validator.js and define new ones using the Callback() Assert.

Validators list

These validators are shipped in parsley.js. Have a look at the Parsley Remote plugin and Parsley Extras for more validators.

Craft yours!

Of course, Parsley built-in validators are commonly used validators, and you'll need some more that fit your specific forms and validations. That's why Parsley lets you easily create your own validators.

Here again, like localizations, configuring your custom validators and error messages comes in two flavors:

• By registering them in globals before loading parsley.js:

  <input type="text" data-parsley-multipleof="3" />
  [...]
  <script type="text/javascript">
  window.ParsleyConfig = {
    validators: {
      multipleof: {
        fn: function (value, requirement) {
          return 0 === value % requirement;
        },
        priority: 32
      }
    },
    i18n: {
      en: {
        multipleof: 'This value should be a multiple of %s'
      },
      fr: {
        multipleof: 'Cette valeur doit être un multiple de %s'
      }
    }
  };
  </script>
  

• By registering them in ParsleyValidator after parsley.js is loaded:

  <input type="text" data-parsley-multipleof="3" />
  [...]
  <script type="text/javascript">
  window.ParsleyValidator
    .addValidator('multipleof', function (value, requirement) {
      return 0 === value % requirement;
    }, 32)
    .addMessage('en', 'multipleof', 'This value should be a multiple of %s')
    .addMessage('fr', 'multipleof', 'Cette valeur doit être un multiple de %s');
  </script>