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rails--rails/activemodel/lib/active_model/validations/presence.rb
2012-06-25 12:14:50 -05:00

50 lines
2.2 KiB
Ruby

require 'active_support/core_ext/object/blank'
module ActiveModel
# == Active Model Presence Validator
module Validations
class PresenceValidator < EachValidator #:nodoc:
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
# <tt>validates_inclusion_of :field_name, :in => [true, false]</tt>.
#
# This is due to the way Object#blank? handles boolean values:
# <tt>false.blank? # => true</tt>.
#
# Configuration options:
# * <tt>:message</tt> - A custom error message (default is: "can't be blank").
# * <tt>:on</tt> - Specifies when this validation is active. Runs in all
# validation contexts by default (+nil+), other options are <tt>:create</tt>
# and <tt>:update</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>:strict</tt> - Specifies whether validation should be strict.
# See <tt>ActiveModel::Validation#validates!</tt> for more information.
def validates_presence_of(*attr_names)
validates_with PresenceValidator, _merge_attributes(attr_names)
end
end
end
end