instiki/vendor/rails/activemodel/lib/active_model/validations/presence.rb
Jacques Distler 516d6dfac0 Rails 2.1
Update to Rails 2.1 final.
2008-06-02 01:35:38 -05:00

42 lines
2.1 KiB
Ruby

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:
# * <tt>:message</tt> - A custom error message (default is: "can't be blank")
# * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <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.
def validates_presence_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:blank], :on => :save }
configuration.update(attr_names.extract_options!)
# can't use validates_each here, because it cannot cope with nonexistent attributes,
# while errors.add_on_empty can
send(validation_method(configuration[:on]), configuration) do |record|
record.errors.add_on_blank(attr_names, configuration[:message])
end
end
end
end
end