Class: Module

Inherits:
Object show all
Includes:
AntSupport::CoreExtensions::Module
Defined in:
lib/ant_support/core_ext/module/attribute_accessors.rb,
lib/ant_support/core_ext/module.rb,
lib/ant_support/core_ext/module/attr_accessor_with_default.rb

Overview

Extends the module object with module and instance accessors for class attributes, just like the native attr* accessors for instance attributes.

module AppConfiguration
  mattr_accessor :google_api_key
  self.google_api_key = "123456789"

  mattr_accessor :paypal_url
  self.paypal_url = "www.sandbox.paypal.com"
end

AppConfiguration.google_api_key = "overriding the api key!"

Instance Method Summary collapse

Methods included from AntSupport::CoreExtensions::Module

#alias_attribute, #alias_method_chain

Instance Method Details

#attr_accessor_with_default(sym, default = nil, &block) ⇒ Object

Declare an attribute accessor with an initial default return value.

To give attribute :age the initial value 25:

class Person
  attr_accessor_with_default :age, 25
end

some_person.age
=> 25
some_person.age = 26
some_person.age
=> 26

To give attribute :element_name a dynamic default value, evaluated in scope of self:

attr_accessor_with_default(:element_name) { name.underscore }



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# File 'lib/ant_support/core_ext/module/attr_accessor_with_default.rb', line 21

def attr_accessor_with_default(sym, default = nil, &block)
  raise 'Default value or block required' unless !default.nil? || block
  define_method(sym, block_given? ? block : Proc.new { default })
  module_eval(<<-EVAL, __FILE__, __LINE__)
    def #{sym}=(value)
      class << self; attr_reader :#{sym} end
      @#{sym} = value
    end
  EVAL
end

#mattr_accessor(*syms) ⇒ Object 



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# File 'lib/ant_support/core_ext/module/attribute_accessors.rb', line 54

def mattr_accessor(*syms)
  mattr_reader(*syms)
  mattr_writer(*syms)
end

#mattr_reader(*syms) ⇒ Object 



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# File 'lib/ant_support/core_ext/module/attribute_accessors.rb', line 14

def mattr_reader(*syms)
  syms.each do |sym|
    next if sym.is_a?(Hash)
    class_eval(<<-EOS, __FILE__, __LINE__)
      unless defined? @@#{sym}
        @@#{sym} = nil
      end
      
      def self.#{sym}
        @@#{sym}
      end

      def #{sym}
        @@#{sym}
      end
    EOS
  end
end

#mattr_writer(*syms) ⇒ Object 



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# File 'lib/ant_support/core_ext/module/attribute_accessors.rb', line 33

def mattr_writer(*syms)
  options = syms.extract_options!
  syms.each do |sym|
    class_eval(<<-EOS, __FILE__, __LINE__)
      unless defined? @@#{sym}
        @@#{sym} = nil
      end
      
      def self.#{sym}=(obj)
        @@#{sym} = obj
      end
      
      #{"
      def #{sym}=(obj)
        @@#{sym} = obj
      end
      " unless options[:instance_writer] == false }
    EOS
  end
end