EachValidator is a validator which iterates through the attributes given in the options hash invoking the validate_each method passing in the record, attribute and value.

All Active Model validations are built on top of this validator.

Methods
C
N
V
Attributes
[R] attributes
Class Public methods
new(options)

Returns a new validator instance. All options will be available via the options reader, however the :attributes option will be removed and instead be made available through the attributes reader.

Source: show | on GitHub 

# File activemodel/lib/active_model/validator.rb, line 139
def initialize(options)
  @attributes = Array.wrap(options.delete(:attributes))
  raise ":attributes cannot be blank" if @attributes.empty?
  super
  check_validity!
end
Instance Public methods
check_validity!()

Hook method that gets called by the initializer allowing verification that the arguments supplied are valid. You could for example raise an ArgumentError when invalid options are supplied.

Source: show | on GitHub 

# File activemodel/lib/active_model/validator.rb, line 166
def check_validity!
end
validate(record)

Performs validation on the supplied record. By default this will call validates_each to determine validity therefore subclasses should override validates_each with validation logic.

Source: show | on GitHub 

# File activemodel/lib/active_model/validator.rb, line 149
def validate(record)
  attributes.each do |attribute|
    value = record.read_attribute_for_validation(attribute)
    next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
    validate_each(record, attribute, value)
  end
end
validate_each(record, attribute, value)

Override this method in subclasses with the validation logic, adding errors to the records errors array where necessary.

Source: show | on GitHub 

# File activemodel/lib/active_model/validator.rb, line 159
def validate_each(record, attribute, value)
  raise NotImplementedError, "Subclasses must implement a validate_each(record, attribute, value) method"
end