require 'active_support/core_ext/object/blank' module ActiveModel # == Active Model Presence Validator module Validations class PresenceValidator < EachValidator def validate(record) record.errors.add_on_blank(attributes, options) end end module HelperMethods # Validates that the specified attributes are not blank (as defined by # Object#blank?). Happens by default on save. # # 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. Runs in all # validation contexts by default (+nil+), other options are :create # and :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. # * :strict - Specifies whether validation should be strict. # See ActiveModel::Validation#validates! for more information. def validates_presence_of(*attr_names) validates_with PresenceValidator, _merge_attributes(attr_names) end end end end