lib/mutations/string_filter.rb
module Mutations
class StringFilter < AdditionalFilter
@default_options = {
:strip => true, # true calls data.strip if data is a string
:strict => false, # If false, then symbols, numbers, and booleans are converted to a string with to_s.
:nils => false, # true allows an explicit nil to be valid. Overrides any other options
:empty_is_nil => false, # if true, treat empty string as if it were nil
:empty => false, # false disallows "". true allows "" and overrides any other validations (b/c they couldn't be true if it's empty)
:min_length => nil, # Can be a number like 5, meaning that 5 codepoints are required
:max_length => nil, # Can be a number like 10, meaning that at most 10 codepoints are permitted
:matches => nil, # Can be a regexp
:in => nil, # Can be an array like %w(red blue green)
:discard_empty => false, # If the param is optional, discard_empty: true drops empty fields.
:allow_control_characters => false # false removes control characters from the string
}
def filter(data)
# Handle nil case
if data.nil?
return [nil, nil] if options[:nils]
return [nil, :nils]
end
# At this point, data is not nil. If it's not a string, convert it to a string for some standard classes
data = data.to_s if !options[:strict] && [TrueClass, FalseClass, Integer, Float, BigDecimal, Symbol].any? { |klass| data.is_a?(klass) }
# Now ensure it's a string:
return [data, :string] unless data.is_a?(String)
# At this point, data is a string. Now remove control characters from the string:
data = data.gsub(/((?=[[:cntrl:]])[^\t\r\n])+/, ' ') unless options[:allow_control_characters]
# Transform it using strip:
data = data.strip if options[:strip]
# Now check if it's blank:
if data == ""
if options[:empty_is_nil]
return [nil, (:nils unless options[:nils])]
elsif options[:empty]
return [data, nil]
else
return [data, :empty]
end
end
# Now check to see if it's the correct size:
return [data, :min_length] if options[:min_length] && data.length < options[:min_length]
return [data, :max_length] if options[:max_length] && data.length > options[:max_length]
# Ensure it match
return [data, :in] if options[:in] && !options[:in].include?(data)
# Ensure it matches the regexp
return [data, :matches] if options[:matches] && (options[:matches] !~ data)
# We win, it's valid!
[data, nil]
end
end
end