Class: Leeroy::Types::Enum

Inherits:
TypesafeEnum::Base
  • Object
show all
Defined in:
lib/leeroy/types/enum.rb

Overview

Implements the [Typesafe Enum pattern](www.oracle.com/technetwork/java/page1-139488.html#replaceenums). Implement your own classes that inherit from this.

Valid values for these enums must be Strings or otherwise stringifiable.

Usage: “‘ class EnumClass < Leeroy::Types::Enum

# 'foo' and 'bar' are the only acceptable values for EnumClass
new :FOO
new :BAR

end

enum_valid = Leeroy::Types::EnumClass.resolve(‘foo’) # returns a valid instance of Leeroy::Types::EnumClass::FOO enum_valid.to_s # returns ‘foo’ enum_invalid = Leeroy::Types::EnumClass.resolve(‘baz’) # raises an exception “‘

Direct Known Subclasses

Fixture, Phase

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.from_s(x) ⇒ Object 



60
61
62
 
# File 'lib/leeroy/types/enum.rb', line 60

def self.from_s(x)
  self.find_by_value_str(x.to_s)
end

.resolve(candidate, alternate = nil) ⇒ Object

Given a string or something that can be stringified, returns a subclass of the parent enum with a value matching the provided string.

Accepts an optional second argument; if the first argument cannot be resolved by the enum, the second argument will be resolved.



43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/leeroy/types/enum.rb', line 43

def self.resolve(candidate, alternate = nil)
  resolved = candidate.kind_of?(Leeroy::Types::Enum) ? candidate : self.from_s(candidate)

  if candidate.nil?
    resolved = self.resolve(alternate, nil) unless alternate.nil?
  end

  # FIXME raise some more appropriate type of error
  raise "invalid value for enum" if resolved.nil?

  resolved
end

Instance Method Details

#from_s(x) ⇒ Object 



64
65
66
 
# File 'lib/leeroy/types/enum.rb', line 64

def from_s(x)
  self.from_s(x)
end

#resolve(candidate, alternate = nil) ⇒ Object 



56
57
58
 
# File 'lib/leeroy/types/enum.rb', line 56

def resolve(candidate, alternate = nil)
  self.resolve(candidate, alternate)
end

#to_s ⇒ Object 



32
33
34
 
# File 'lib/leeroy/types/enum.rb', line 32

def to_s
  self.value
end