require 'iconv' # # Given a string, tell us whether or not is acceptable. Also, remove stuff we don't like # such as leading / trailing space. # class TextSentinel attr_accessor :text def self.non_symbols_regexp /[\ -\/\[-\`\:-\@\{-\~]/m end def initialize(text, opts=nil) if text.present? @text = Iconv.new('UTF-8//IGNORE', 'UTF-8').iconv(text.dup) end @opts = opts || {} if @text.present? @text.strip! @text.gsub!(/ +/m, ' ') if @opts[:remove_interior_spaces] end end # Entropy is a number of how many unique characters the string needs. def entropy return 0 if @text.blank? @entropy ||= @text.each_char.to_a.uniq.size end def valid? # Blank strings are not valid return false if @text.blank? # Entropy check if required return false if @opts[:min_entropy].present? and (entropy < @opts[:min_entropy]) # We don't have a comprehensive list of symbols, but this will eliminate some noise non_symbols = @text.gsub(TextSentinel.non_symbols_regexp, '').size return false if non_symbols == 0 # Don't allow super long strings without spaces return false if @opts[:max_word_length] and @text =~ /\w{#{@opts[:max_word_length]},}(\s|$)/ # We don't allow all upper case content return false if @text == @text.upcase true end end