FlagSet is a Ruby library to make sets of finite flags.
gem install flagset
You define a class with FlagSet.define:
Auth = FlagSet.define{
flag :allow_read_name
flag :allow_read_email
flag :allow_read_posts
}Simpler ways are also available:
Auth = FlagSet.define{
flag :allow_read_name, :allow_read_email, :allow_read_posts
}Or
Auth = FlagSet.define(:allow_read_name, :allow_read_email, :allow_read_posts)Auth.new
# => #<Auth: []> (empty set)
Auth.new(:allow_read_name, :allow_read_posts)
# => #<Auth: [:allow_read_name,:allow_read_posts]>
Auth[:allow_read_name, :allow_read_posts]
# => #<Auth: [:allow_read_name,:allow_read_posts]> (same as above)Auth.allow_read_email
# => #<Auth: [:allow_read_email]> (same as Auth.new(:allow_read_email))
Auth.allow_read_name | Auth.allow_read_posts
# => #<Auth: [:allow_read_name,:allow_read_posts]>You can use special name all and none
Auth.all
# => #<Auth: [:allow_read_name,:allow_read_email,:allow_read_posts]>
Auth.none
# => #<Auth: []>all and none are aliases that denotes set of flags. You can also define aliases your own.
Auth2 = FlagSet.define{
aliased :read_all, [:read_name, :read_email, :read_posts]
flag :read_name, :read_email, :read_posts
flag :write_posts, :write_messages
aliased :write_all, [:write_posts, :write_messages]
# You can put aliased before or after the original names
aliased :read_write_all, [:read_all, :write_all]
}
Auth2.read_all
# => #<Auth2: [:read_name,:read_email,:read_posts]>
Auth2.write_all
# => #<Auth2: [:write_posts,:write_messages]>
Auth2.read_write_all == Auth2.all
# => trueYou can check the state of the flags with has_all_of? and has_any_of? methods:
Auth2.read_name.has_all_of?(:read_all)
# => false
Auth2.read_all.has_all_of?(:read_name, :read_email)
# => true
Auth2.write_all.has_all_of?(Auth2[:write_posts, :write_messages])
# => true
Auth2[:read_all].has_any_of?(:read_posts)
# => true
Auth2.read_all.has_any_of?(:write_all)
# => false
Auth2.all.has_any_of?(:none)
# => falseYou can also use named query methods:
Auth2.read_all.read_name?
# => true
Auth2.write_posts.write_all?
# => trueNote that the query method #foo? is equivalent to has_any_of?(:foo), so aliases can be confusing when used as query methods.
There are special query methods all?, any?, none?
# #all? returns true if self is equal to class.all
Auth2.read_all.all? #=> false
(Auth2.read_all | Auth2.write_all).all? #=> true
# #any? returns true if self is not equal to class.none
Auth2.read_email.any? # => true
Auth2.new.any? # => false
# #none? returns true if self is equal to class.none
Auth2.read_posts.none? #=> false
Auth2.none.none? #=> trueBasic set operations are supported.
Auth2.read_all & Auth2.read_name
# => #<Auth2: [:read_name]>
Auth2.read_name | Auth2.read_email
# => #<Auth2: [:read_name,:read_email]>
Auth2.read_all - :read_posts
# => #<Auth2: [:read_name,:read_email]>
Auth2[:read_name, :read_email] ^ [:read_email, :read_posts]
# => #<Auth2: [:read_name,:read_posts]>
~Auth2[:write_all]
# => #<Auth2: [:read_name,:read_email,:read_posts]>The arguments of .new and set operations can be one of these:
- Symbol
- the same class as self
- Integer
or a single Array of above.
MIT License