method

extlib_inheritable_reader

v3.0.0 - Show latest stable - Class: Class

extlib_inheritable_reader(*ivars, &block)

public

Defines class-level inheritable attribute reader. Attributes are available to subclasses, each subclass has a copy of parent’s attribute.

@param *syms<Array[#to_s]> Array of attributes to define inheritable reader for. @return <Array[#to_s]> Array of attributes converted into inheritable_readers.

@api public

@todo Do we want to block instance_reader via :instance_reader => false @todo It would be preferable that we do something with a Hash passed in

  (error out or do the same as other methods above) instead of silently
  moving on). In particular, this makes the return value of this function
  less useful.

# File activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb, line 191
  def extlib_inheritable_reader(*ivars, &block)
    options = ivars.extract_options!

    ivars.each do |ivar|
      self.class_eval "def self.\#{ivar}\nreturn @\#{ivar} if self.object_id == \#{self.object_id} || defined?(@\#{ivar})\nivar = superclass.\#{ivar}\nreturn nil if ivar.nil? && !\#{self}.instance_variable_defined?(\"@\#{ivar}\")\n@\#{ivar} = ivar.duplicable? ? ivar.dup : ivar\nend\n", __FILE__, __LINE__ + 1
      unless options[:instance_reader] == false
        self.class_eval "def \#{ivar}\nself.class.\#{ivar}\nend\n", __FILE__, __LINE__ + 1
      end
      instance_variable_set("@#{ivar}""@#{ivar}", yield) if block_given?
    end
  end

extlib_inheritable_reader

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