Youyouaidi revised

Youyouaidi revised is a Ruby Gem that offers a UUID class for generating, parsing, validating and converting UUIDs into / from shorter representations.

This gem is a fork of the unmaintained repo at http://github.com/nicolas-fricke/youyouaidi. Many thanks to the original author! 😊

While a UUID consists of 36 characters – 32 hexadecimal characters, divided by four dashes into five subgroups – the short representation (invoked via #to_short_string) consists of exactly 22 digit and lower- and uppercase characters.

This is what a valid, random (version 4) UUID looks like:

                          version    either 8, 9
                           number    a, or b
                                ▼    ▼
                  caed3f49-b0ca-454b-adf8-5ee2a1764759
# chars in group:     8   | 4  | 4  | 4  |    12

As shown, the first digit of the third group indicates the UUID version. The first digit of the fourth group always has to be one of either 8, 9, a, or b. All other digits are randomly assigned hexadecimals.

And this is the same UUID in its short format: 6aUS5foeLu2VGDspRPc7bz.

For UUID generation, the SecureRandom.uuid method is used which generates valid, random version 4 UUIDs.

Find out more about UUIDs and the different versions on Wikipedia.

Installation

Add this line to your application's Gemfile:

gem 'youyouaidi-revised'

And then execute:

$ bundle

Or install it yourself as:

$ gem install youyouaidi-revised

Usage

UUID(...) was patched in the kernel. Not anymore. We don't patch the kernel unless we have no other choice. This means this gem is not backwards compatible.

require 'youyouaidi'

# Use youyouaidi

Initializing UUIDs

uuid_string = '550e8400-e29b-41d4-a716-446655440000' # A valid UUID in string format, has exactly 32 hexadecimal characters in 5 groups
uuid_short  = '2AuYQJcZeiIeCymkJ7tzTW'               # Same UUID in its short format, has exactly 22 characters of [0-9a-zA-Z]

uuid = Youyouaidi::UUID.parse uuid_string   # creates new Youyouaidi::UUID object
# => #<Youyouaidi::UUID:0x000001021f2590 @converter=Youyouaidi::Converter, @uuid="550e8400-e29b-41d4-a716-446655440000">

# Alternatively a short UUID can be passed:
uuid = Youyouaidi::UUID.parse uuid_short    # creates similar Youyouaidi::UUID object
# => #<Youyouaidi::UUID:0x00000102201b80 @converter=Youyouaidi::Converter, @uuid="550e8400-e29b-41d4-a716-446655440000">

# To generate a new random UUID simply do not pass a parameter:
new_uuid = Youyouaidi::UUID.new       # generates a random UUID version 4 using the SecureRandom.uuid method
# => #<Youyouaidi::UUID:0x00000102201b80 @converter=Youyouaidi::Converter, @uuid="27f8bc29-be8e-4dc7-ab30-0295b2a5e902">

Validity check and conversions

The validity check Youyouaidi::UUID.valid? uuid_string checks, if UUID contains exactly 32 hexadecimal characters which are divided by four dashes ('-') into five groups of sizes 8, 4, 4, 4, and 12. Also, it validates that the first character of the fourth group is either a 8, 9, an a, or a b.

uuid_string = '550e8400-e29b-41d4-a716-446655440000' # A valid UUID in string format
uuid = Youyouaidi::UUID uuid_string

Youyouaidi::UUID.valid? uuid_string # Checks if `uuid_string' is a valid UUID, same as Youyouaidi::UUID.valid? uuid_string
# => true

uuid.to_s               # Returns the string representation of the UUID object
# => '550e8400-e29b-41d4-a716-446655440000'

uuid.to_short_string    # Returns the short string representation of the UUID object, #to_param is an alias for this method
# => '2AuYQJcZeiIeCymkJ7tzTW'

Comparing UUIDs

uuid_string  = '550e8400-e29b-41d4-a716-446655440000' # A valid UUID in string format
uuid         = Youyouaidi::UUID.parse uuid_string
similar_uuid = Youyouaidi::UUID.parse uuid_string
other_uuid   = Youyouaidi::UUID.parse '00000000-1111-2222-aaaa-eeeeeeeeeeee'

uuid == similar_uuid # Two UUID objects representing same UUID (#=== behaves similar for this)
# => true

uuid == other_uuid   # Two UUID objects representing different UUIDs (#=== behaves similar for this)
# => false

uuid == uuid_string  # Comparing a UUID object and its string representation with `=='
# => false

uuid === uuid_string # Comparing a UUID object and its string representation with `===' (case insensetive)
# => true

Contributing

Fork it ( http://github.com/lorankloeze/youyouaidi-revised/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request

Build gem

gem build youyouaidi-revised.gemspec
gem install ./youyouaidi-revised-x.x.gem