Method: ActiveModel::Validations::ClassMethods#validates_with

Defined in:

lib/active_model/validations/with.rb

#validates_with(*args, &block) ⇒ Object

Passes the record off to the class or classes specified and allows them to add errors based on more complex conditions.

class Person
  include ActiveModel::Validations
  validates_with MyValidator
end

class MyValidator < ActiveModel::Validator
  def validate(record)
    if some_complex_logic
      record.errors[:base] << "This record is invalid"
    end
  end

  private
    def some_complex_logic
      # ...
    end
end

You may also pass it multiple classes, like so:

class Person
  include ActiveModel::Validations
  validates_with MyValidator, MyOtherValidator, :on => :create
end

Configuration options:

• on - Specifies when this validation is active (:create or :update

• if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

• unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.

If you pass any additional configuration options, they will be passed to the class and available as options:

class Person
  include ActiveModel::Validations
  validates_with MyValidator, :my_custom_key => "my custom value"
end

class MyValidator < ActiveModel::Validator
  def validate(record)
    options[:my_custom_key] # => "my custom value"
  end
end

# File 'lib/active_model/validations/with.rb', line 67

def validates_with(*args, &block)
  options = args.extract_options!
  args.each do |klass|
    validator = klass.new(options, &block)
    validator.setup(self) if validator.respond_to?(:setup)

    if validator.respond_to?(:attributes) && !validator.attributes.empty?
      validator.attributes.each do |attribute|
        _validators[attribute.to_sym] << validator
      end
    else
      _validators[nil] << validator
    end

    validate(validator, options)
  end
end