lib/file_size_validator.rb
# lib/file_size_validator.rb
# Based on: https://gist.github.com/795665
class FileSizeValidator < ActiveModel::EachValidator
MESSAGES = {
is: :wrong_size,
minimum: :size_too_small,
maximum: :size_too_big
}.freeze
CHECKS = {
is: :==,
minimum: :>=,
maximum: :<=
}.freeze
DEFAULT_TOKENIZER = lambda { |value| value.split(//) }
RESERVED_OPTIONS = [
:minimum, :maximum, :within, :is,
:tokenizer, :too_short, :too_long
]
def initialize(options)
if range = (options.delete(:in) || options.delete(:within))
raise ArgumentError, ':in and :within must be a Range' unless range.is_a?(Range)
options[:minimum], options[:maximum] = range.begin, range.end
options[:maximum] -= 1 if range.exclude_end?
end
super
end
def check_validity!
keys = CHECKS.keys & options.keys
if keys.empty?
raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
end
keys.each do |key|
value = options[key]
unless value.is_a?(Integer) && value >= 0
raise ArgumentError, ":#{key} must be a nonnegative Integer"
end
end
end
def validate_each(record, attribute, value)
raise(ArgumentError, 'A CarrierWave::Uploader::Base object was expected') unless value.kind_of? CarrierWave::Uploader::Base
value = (options[:tokenizer] || DEFAULT_TOKENIZER).call(value) if value.kind_of?(String)
CHECKS.each do |key, validity_check|
next unless check_value = options[key]
value ||= [] if key == :maximum
value_size = value.size
next if value_size.send(validity_check, check_value)
errors_options = options.except(*RESERVED_OPTIONS)
errors_options[:file_size] = help.number_to_human_size check_value
default_message = options[MESSAGES[key]]
errors_options[:message] ||= default_message if default_message
record.errors.add(attribute, MESSAGES[key], errors_options)
end
end
def help
Helper.instance
end
class Helper
include Singleton
include ActionView::Helpers::NumberHelper
end
end