lib/flag_shih_tzu/validators.rb
# Active Record is not defined as a runtime dependency in the gemspec.
unless defined?(::ActiveRecord)
begin
# If by some miracle it hasn't been loaded yet, try to load it.
require "active_record"
rescue LoadError
# If it fails to load, then assume the user is try to use flag_shih_tzu with some other database adapter
warn "FlagShihTzu probably won't work unless you have some version of Active Record loaded. Versions >= 2.3 are supported."
end
end
if defined?(::ActiveRecord) && ::ActiveRecord::VERSION::MAJOR >= 3
module ActiveModel
# Open ActiveModel::Validations to define some additional ones
module Validations
# A simple EachValidator that will check for the presence of the flags specified
class PresenceOfFlagsValidator < EachValidator
def validate_each(record, attribute, value)
value = record.send(:read_attribute_for_validation, attribute)
check_flag(record, attribute)
record.errors.add(attribute, :blank, options) if value.blank? || value == 0
end
private
def check_flag(record, attribute)
unless record.class.flag_columns.include? attribute.to_s
raise ArgumentError.new("#{attribute} is not one of the flags columns (#{record.class.flag_columns.join(', ')})")
end
end
end
# Use these validators in your model
module HelperMethods
# Validates that the specified attributes are flags and are not blank.
# Happens by default on save. Example:
#
# class Spaceship < ActiveRecord::Base
# include FlagShihTzu
#
# has_flags({ 1 => :warpdrive, 2 => :hyperspace }, :column => 'engines')
# validates_presence_of_flags :engines
# end
#
# The engines attribute must be a flag in the object and it cannot be blank.
#
# 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 { |spaceship| spaceship.warp_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_flags(*attr_names)
validates_with PresenceOfFlagsValidator, _merge_attributes(attr_names)
end
end
end
end
end