Youyouaidi
Youyouaidi
is a Ruby Gem that offers a UUID class for generating, parsing, validating and converting UUIDs into / from shorter representations.
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'
And then execute:
$ bundle
Or install it yourself as:
$ gem install youyouaidi
Usage
For usability, UUID(...)
is patched into the kernel as a shorthand call to Youyouaidi::UUID.parse(...)
.
Also, UUID
is patched as a reference for the class Youyouid::UUID
.
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 = UUID uuid_string # creates new Youyouaidi::UUID object, patches Youyouaidi::UUID.parse uuid_string into kernel.
# => #<Youyouaidi::UUID:0x000001021f2590 @converter=Youyouaidi::Converter, @uuid="550e8400-e29b-41d4-a716-446655440000">
# Alternatively a short UUID can be passed:
uuid = UUID 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 = UUID() # 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 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 = UUID uuid_string
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 = UUID uuid_string
similar_uuid = UUID uuid_string
other_uuid = UUID '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/nicolas-fricke/youyouaidi/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