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module ActiveModel
module Validations
class FormatValidator < EachValidator # :nodoc:
def validate_each(record, attribute, value)
if options[:with]
regexp = option_call(record, :with)
record_error(record, attribute, :with, value) if value.to_s !~ regexp
elsif options[:without]
regexp = option_call(record, :without)
record_error(record, attribute, :without, value) if regexp.match?(value.to_s)
end
end
def check_validity!
unless options.include?(:with) ^ options.include?(:without) # ^ == xor, or "exclusive or"
raise ArgumentError, "Either :with or :without must be supplied (but not both)"
end
check_options_validity :with
check_options_validity :without
end
private
def option_call(record, name)
option = options[name]
option.respond_to?(:call) ? option.call(record) : option
end
def record_error(record, attribute, name, value)
record.errors.add(attribute, :invalid, options.except(name).merge!(value: value))
end
def check_options_validity(name)
if option = options[name]
if option.is_a?(Regexp)
if options[:multiline] != true && regexp_using_multiline_anchors?(option)
raise ArgumentError, "The provided regular expression is using multiline anchors (^ or $), " \
"which may present a security risk. Did you mean to use \\A and \\z, or forgot to add the " \
":multiline => true option?"
end
elsif !option.respond_to?(:call)
raise ArgumentError, "A regular expression or a proc or lambda must be supplied as :#{name}"
end
end
end
def regexp_using_multiline_anchors?(regexp)
source = regexp.source
source.start_with?("^") || (source.end_with?("$") && !source.end_with?("\\$"))
end
end
module HelperMethods
# Validates whether the value of the specified attribute is of the correct
# form, going by the regular expression provided. You can require that the
# attribute matches the regular expression:
#
# class Person < ActiveRecord::Base
# validates_format_of :email, with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, on: :create
# end
#
# Alternatively, you can require that the specified attribute does _not_
# match the regular expression:
#
# class Person < ActiveRecord::Base
# validates_format_of :email, without: /NOSPAM/
# end
#
# You can also provide a proc or lambda which will determine the regular
# expression that will be used to validate the attribute.
#
# class Person < ActiveRecord::Base
# # Admin can have number as a first letter in their screen name
# validates_format_of :screen_name,
# with: ->(person) { person.admin? ? /\A[a-z0-9][a-z0-9_\-]*\z/i : /\A[a-z][a-z0-9_\-]*\z/i }
# end
#
# Note: use <tt>\A</tt> and <tt>\z</tt> to match the start and end of the
# string, <tt>^</tt> and <tt>$</tt> match the start/end of a line.
#
# Due to frequent misuse of <tt>^</tt> and <tt>$</tt>, you need to pass
# the <tt>multiline: true</tt> option in case you use any of these two
# anchors in the provided regular expression. In most cases, you should be
# using <tt>\A</tt> and <tt>\z</tt>.
#
# You must pass either <tt>:with</tt> or <tt>:without</tt> as an option.
# In addition, both must be a regular expression or a proc or lambda, or
# else an exception will be raised.
#
# Configuration options:
# * <tt>:message</tt> - A custom error message (default is: "is invalid").
# * <tt>:with</tt> - Regular expression that if the attribute matches will
# result in a successful validation. This can be provided as a proc or
# lambda returning regular expression which will be called at runtime.
# * <tt>:without</tt> - Regular expression that if the attribute does not
# match will result in a successful validation. This can be provided as
# a proc or lambda returning regular expression which will be called at
# runtime.
# * <tt>:multiline</tt> - Set to true if your regular expression contains
# anchors that match the beginning or end of lines as opposed to the
# beginning or end of the string. These anchors are <tt>^</tt> and <tt>$</tt>.
#
# There is also a list of default options supported by every validator:
# +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
# See <tt>ActiveModel::Validation#validates</tt> for more information
def validates_format_of(*attr_names)
validates_with FormatValidator, _merge_attributes(attr_names)
end
end
end
end
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