Validators

Add some nice ActiveModel/ActiveRecord validators.

gem install validators

Then add it to your Gemfile:

gem "validators"

Notice: Some validators will require additional dependencies; whenever you get a message like gem-name is not part of the bundle. Add it to your project's Gemfile., all you have to do is adding that gem to your own project's Gemfile.

class User < ActiveRecord::Base
  # old fashion
  validates_email_format_of :email

  # alternative way
  validates :email, email: true
end

By default, it rejects disposable e-mails (e.g. mailinator). This loads a lot of data (~1.7MB), but you can disable this validation by setting disposable: true.

class User < ActiveRecord::Base
  validates_email_format_of :email, disposable: true
end

You can also validate the tld.

class User < ActiveRecord::Base
  validates_email_format_of :email, tld: true
end

class User < ActiveRecord::Base
  validates_url_format_of :site

  # validates TLD against list of valid TLD.
  # Loads ~10KB of text.
  validates_url_format_of :site, tld: true
end

class Task < ActiveRecord::Base
  belongs_to :user
  belongs_to :category

  validates_ownership_of :category, with: :user
end

user = User.find(1)
another_user = User.find(2)

user_category = user.categories.first
another_user_category = another_user.categories.first

task = user.tasks.create(category: user_category)
task.valid?
#=> true

task = user.tasks.create(category: another_user_category)
task.valid?
#=> false

class Server < ActiveRecord::Base
  validates_ip_address :address
  validates_ip_address :address, only: :v4
  validates_ip_address :address, only: :v6
end

class Server < ActiveRecord::Base
  validates_datetime :starts_at
  validates_datetime :ends_at, after: :starts_at, if: :starts_at?
  validates_datetime :ends_at, after: :now
  validates_datetime :ends_at, before: :today

  validates :starts_at, datetime: true
end

class User < ActiveRecord::Base
  validates_cpf_format_of :document
end

class User < ActiveRecord::Base
  validates_cnpj_format_of :document
end

Rules:

• maximum length of hostname is 255 characters
• maximum length of each hostname label is 63 characters
• characters allowed in hostname labels are a-z, A-Z, 0-9 and hyphen
• labels do not begin or end with a hyphen
• labels do not consist of numeric values only
• TLD validation (optional)

class Server < ActiveRecord::Base
  validates_hostname :hostname
  validates_hostname :hostname, tld: true
end

A valid username/subdomain follows the hostname label validation:

• maximum length is 63 characters
• allowed characters are a-z, A-Z, 0-9 and hyphen
• cannot begin or end with a hyphen
• cannot consist of numeric values only

The compiled list will be used for both username and subdomain validations. This validation loads ~20KB of text.

class Server < ActiveRecord::Base
  validates_subdomain :subdomain
end

class User < ActiveRecord::Base
  validates_username :username
end

You can also provide your own list if you want. Any string that starts with / will be parsed with Regexp.compile.

ReservedUsernames = Validators::ReservedHostnames.parse_list([
  "www",
  "/www[0-9-]+/"
])

class User < ActiveRecord::Base
  validates_username :username, in: ReservedUsernames
end

To disable the reserved validation, use reserved: false.

class User < ActiveRecord::Base
  validates_username :username, reserved: false
end

• Nando Vieira

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.