require 'active_support/core_ext/hash/slice'
module ActiveModel
module Validations
module ClassMethods
# This method is a shortcut to all default validators and any custom
# validator classes ending in 'Validator'. Note that Rails default
# validators can be overridden inside specific classes by creating
# custom validator classes in their place such as PresenceValidator.
#
# Examples of using the default rails validators:
#
# validates :terms, acceptance: true
# validates :password, confirmation: true
# validates :username, exclusion: { in: %w(admin superuser) }
# validates :email, format: { with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, on: :create }
# validates :age, inclusion: { in: 0..9 }
# validates :first_name, length: { maximum: 30 }
# validates :age, numericality: true
# validates :username, presence: true
# validates :username, uniqueness: true
#
# The power of the +validates+ method comes when using custom validators
# and default validators in one call for a given attribute.
#
# class EmailValidator < ActiveModel::EachValidator
# def validate_each(record, attribute, value)
# record.errors.add attribute, (options[:message] || "is not an email") unless
# value =~ /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i
# end
# end
#
# class Person
# include ActiveModel::Validations
# attr_accessor :name, :email
#
# validates :name, presence: true, uniqueness: true, length: { maximum: 100 }
# validates :email, presence: true, email: true
# end
#
# Validator classes may also exist within the class being validated
# allowing custom modules of validators to be included as needed.
#
# class Film
# include ActiveModel::Validations
#
# class TitleValidator < ActiveModel::EachValidator
# def validate_each(record, attribute, value)
# record.errors.add attribute, "must start with 'the'" unless value =~ /\Athe/i
# end
# end
#
# validates :name, title: true
# end
#
# Additionally validator classes may be in another namespace and still
# used within any class.
#
# validates :name, :'film/title' => true
#
# The validators hash can also handle regular expressions, ranges, arrays
# and strings in shortcut form.
#
# validates :email, format: /@/
# validates :gender, inclusion: %w(male female)
# validates :password, length: 6..20
#
# When using shortcut form, ranges and arrays are passed to your
# validator's initializer as <tt>options[:in]</tt> while other types
# including regular expressions and strings are passed as <tt>options[:with]</tt>.
#
# There is also a list of options that could be used along with validators:
#
# * <tt>:on</tt> - Specifies the contexts where this validation is active.
# Runs in all validation contexts by default (nil). You can pass a symbol
# or an array of symbols. (e.g. <tt>on: :create</tt> or
# <tt>on: :custom_validation_context</tt> or
# <tt>on: [:create, :custom_validation_context]</tt>)
# * <tt>:if</tt> - Specifies a method, proc or string to call to determine
# if the validation should occur (e.g. <tt>if: :allow_validation</tt>,
# or <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>). The method,
# proc or string should return or evaluate to a +true+ or +false+ value.
# * <tt>:unless</tt> - Specifies a method, proc or string to call to determine
# if the validation should not occur (e.g. <tt>unless: :skip_validation</tt>,
# or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
# method, proc or string should return or evaluate to a +true+ or
# +false+ value.
# * <tt>:allow_nil</tt> - Skip validation if the attribute is +nil+.
# * <tt>:allow_blank</tt> - Skip validation if the attribute is blank.
# * <tt>:strict</tt> - If the <tt>:strict</tt> option is set to true
# will raise ActiveModel::StrictValidationFailed instead of adding the error.
# <tt>:strict</tt> option can also be set to any other exception.
#
# Example:
#
# validates :password, presence: true, confirmation: true, if: :password_required?
# validates :token, uniqueness: true, strict: TokenGenerationException
#
#
# Finally, the options +:if+, +:unless+, +:on+, +:allow_blank+, +:allow_nil+, +:strict+
# and +:message+ can be given to one specific validator, as a hash:
#
# validates :password, presence: { if: :password_required?, message: 'is forgotten.' }, confirmation: true
def validates(*attributes)
defaults = attributes.extract_options!.dup
validations = defaults.slice!(*_validates_default_keys)
raise ArgumentError, "You need to supply at least one attribute" if attributes.empty?
raise ArgumentError, "You need to supply at least one validation" if validations.empty?
defaults[:attributes] = attributes
validations.each do |key, options|
next unless options
key = "#{key.to_s.camelize}Validator"
begin
validator = key.include?('::') ? key.constantize : const_get(key)
rescue NameError
raise ArgumentError, "Unknown validator: '#{key}'"
end
validates_with(validator, defaults.merge(_parse_validates_options(options)))
end
end
# This method is used to define validations that cannot be corrected by end
# users and are considered exceptional. So each validator defined with bang
# or <tt>:strict</tt> option set to <tt>true</tt> will always raise
# <tt>ActiveModel::StrictValidationFailed</tt> instead of adding error
# when validation fails. See <tt>validates</tt> for more information about
# the validation itself.
#
# class Person
# include ActiveModel::Validations
#
# attr_accessor :name
# validates! :name, presence: true
# end
#
# person = Person.new
# person.name = ''
# person.valid?
# # => ActiveModel::StrictValidationFailed: Name can't be blank
def validates!(*attributes)
options = attributes.extract_options!
options[:strict] = true
validates(*(attributes << options))
end
protected
# When creating custom validators, it might be useful to be able to specify
# additional default keys. This can be done by overwriting this method.
def _validates_default_keys # :nodoc:
[:if, :unless, :on, :allow_blank, :allow_nil , :strict]
end
def _parse_validates_options(options) # :nodoc:
case options
when TrueClass
{}
when Hash
options
when Range, Array
{ in: options }
else
{ with: options }
end
end
end
end
end
