require 'active_support/core_ext/object/blank'
module ActiveModel
module Validations
module ClassMethods
# Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:
#
# class Person < ActiveRecord::Base
# validates_presence_of :first_name
# end
#
# The first_name attribute must be in the object and it cannot be blank.
#
# If you want to validate the presence of a boolean field (where the real values are true and false),
# you will want to use validates_inclusion_of :field_name, :in => [true, false].
#
# This is due to the way Object#blank? handles boolean values: false.blank? # => true.
#
# Configuration options:
# * message - A custom error message (default is: "can't be blank").
# * on - Specifies when this validation is active (default is :save, other options :create,
# :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.
#
def validates_presence_of(*attr_names)
configuration = attr_names.extract_options!
# can't use validates_each here, because it cannot cope with nonexistent attributes,
# while errors.add_on_empty can
validate configuration do |record|
record.errors.add_on_blank(attr_names, configuration[:message])
end
end
end
end
end