HTML5Validators

Automatic client-side validation using HTML5 Form Validation

What is this?

html5_validators is a gem/plugin for Rails 3+ that enables automatic 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 => required

• 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 four ways to cancel the automatic HTML5 validation.

1. Per form (via form_for option)

Set auto_html5_validation: false to form_for parameter.

• View

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

2. Per model instance (via 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 %>

3. Per model class (via model class attribute)

Set auto_html5_validation = false to ActiveModelish class' class variable. This configuration will never be propagated to inherited children classes.

• Model

class User < ActiveRecord::Base
  self.auto_html5_validation = false
end

• Controller

@user = User.new

• View

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

4. Globally (via HTML5Validators module configuration)

Set config.enabled = false to Html5Validators module. Maybe you want to put this in your test_helper, or add a controller filter as follows for development mode.

• Controller

# an example filter that disables the validator if the request has {h5v: 'disable'} params
around_action do |controller, block|
  h5v_enabled_was = Html5Validators.enabled
  Html5Validators.enabled = false if params[:h5v] == 'disable'
  block.call
  Html5Validators.enabled = h5v_enabled_was
end

Supported versions

• Ruby 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7 (trunk)

• Rails 3.2.x, 4.0.x, 4.1, 4.2, 5.0, 5.1, 5.2, 6.0, 6.1 (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

Copyright

Copyright (c) 2011 Akira Matsuda. See MIT-LICENSE for further details.