HTML5Validators

Automatic client-side validation using HTML5 Form Validation

What is this?

html5_validators is a gem/plugin for Rails 3 that enables client-side validation using ActiveModel + HTML5. Once you bundle this gem on your app, the gem will automatically translate your model validation code into HTML5 validation attributes on every ‘form_for` invocation unless you explicitly cancel it.

Features

PresenceValidator => requried

Model:
  class User
    include ActiveModel::Validations
    validates_presence_of :name
  end

View:
  <%= f.text_field :name %>
  other text_fieldish helpers, text_area, radio_button, and check_box are also available

HTML:
  <input id="user_name" name="user[name]" required="required" type="text" />

SPEC:
  http://dev.w3.org/html5/spec/Overview.html#attr-input-required

LengthValidator => maxlength

Model:
  class User
    include ActiveModel::Validations
    validates_length_of :name, :maximum => 10
  end

View:
  <%= f.text_field :name %>
  text_area is also available

HTML:
  <input id="user_name" maxlength="10" name="user[name]" size="10" type="text" />

SPEC:
  http://dev.w3.org/html5/spec/Overview.html#attr-input-maxlength

NumericalityValidator => max, min

Model:
  class User
    include ActiveModel::Validations
    validates_numericality_of :age, :greater_than_or_equal_to => 20
  end

View: (be sure to use number_field)
  <%= f.number_field :age %>

HTML:
  <input id="user_age" min="20" name="user[age]" size="30" type="number" />

SPEC:
  http://dev.w3.org/html5/spec/Overview.html#attr-input-max
  http://dev.w3.org/html5/spec/Overview.html#attr-input-min

And more (coming soon…?)

Disabling automatic client-side validation

There are three ways to cancel the automatic HTML5 validation

form_for option

Set ‘auto_html5_validation: false` to `form_for` parameter

View:
  <%= form_for @user, :auto_html5_validation => false do |f| %>
    ...
  <% end %>

model attribute

Set ‘auto_html5_validation = false` attribute to ActiveModelish object

Controller:
  @user = User.new auto_html5_validation: false

View:
  <%= form_for @user do |f| %>
    ...
  <% end %>

model class configuration

Write ‘auto_html5_validation = false` in ActiveModelish class

Model:
  class User < ActiveRecord::Base
    auto_html5_validation = false
  end

Controller:
  @user = User.new

View:
  <%= form_for @user do |f| %>
    ...
  <% end %>

Supported versions

Ruby 1.8.7, 1.9.2, 1.9.3, 2.0 (trunk)
Rails 3.0.x, 3.1.x, 3.2.x, 4.0 (edge)
HTML5 compatible browsers

Installation

Put this line into your Gemfile:

gem 'html5_validators'

Then bundle:

% bundle

Notes

When accessed by an HTML5 incompatible lagacy browser, these extra attributes will just be ignored.

Todo

more validations