attr_required

This gem provide attr_required and attr_optional like attr_accessor.

REQUIRED and OPTIONAL are common terminology in RFCs, and used for protocol parameters. This gem helps RFC library developers to define which parameters (attributes in Ruby world) are REQUIRED and which are OPTIONAL. It might be also helpful for other developers.

I’ve developed this gem to use for rack-oauth2, a Rack-based OAuth 2.0 library. github.com/nov/rack-oauth2

Installation

gem install attr_required

Usage

# Attributes Definitions

require 'attr_required'
require 'attr_optional'

class A
  include AttrRequired, AttrOptional
  attr_required :required_a
  attr_optional :optional_a
end

class B < A
  attr_required :required_b
  attr_optional :optional_b
end

# Class Methods

A.required_attributes #=> [:required_a]
B.required_attributes #=> [:required_a, :required_b]
A.optional_attributes #=> [:optional_a]
B.optional_attributes #=> [:optional_a, :optional_b]

A.attr_required?(:required_a) #=> true
B.attr_optional?(:optional_b) #=> true

# Instance Methods

@a = A.new
@b = B.new

@a.required_attributes #=> [:required_a]
@b.required_attributes #=> [:required_a, :required_b]
@a.optional_attributes #=> [:optional_a]
@b.optional_attributes #=> [:optional_a, :optional_b]

@a.attr_required?(:required_a) #=> true
@a.attr_optional?(:optiona_a)  #=> true

@a.attr_missing? #=> true
@a.attr_missing  #=> [:required_a]
@a.attr_missing! #=> raise AttrRequired::AttrMissing
@a.required_a = "foo"
@a.attr_missing? #=> false
@a.attr_missing  #=> []
@a.attr_missing! #=> do nothing

Check spec/attr_(required|optional).rb for more details.

Note on Patches/Pull Requests

Copyright © 2010 nov matake. See LICENSE for details.