Module: Pigeon::OptionAccessor

Included in:
Dispatcher, Engine
Defined in:
lib/pigeon/option_accessor.rb

Instance Method Summary collapse

Instance Method Details

#option_accessor(*args) ⇒ Object

Given a list of names, this declares an option accessor which works like a combination of cattr_accessor and attr_accessor, except that defaults defined for a class will propagate down to the instances and subclasses, but these defaults can be over-ridden in subclasses and instances without interference. Optional hash at end of list can be used to set:

* :default => Assigns a default value which is otherwise nil



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# File 'lib/pigeon/option_accessor.rb', line 8

def option_accessor(*args)
  option_reader(*args)
  option_writer(*args)
end

#option_reader(*names) ⇒ Object

Given a list of names, this declares an option reader which works like a combination of cattr_reader and attr_reader, except that defaults defined for a class will propagate down to the instances and subclasses, but these defaults can be over-ridden in subclasses and instances without interference. Optional hash at end of list can be used to set:

* :default => Assigns a default value which is otherwise nil
* :boolean => If true, creates an additional name? method and will
              convert all assigned values to a boolean true/false.



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# File 'lib/pigeon/option_accessor.rb', line 21

def option_reader(*names)
  names = [ names ].flatten.compact
  options = names.last.is_a?(Hash) ? names.pop : { }
  
  names.each do |name|
    iv = :"@#{name}"

    (class << self; self; end).class_eval do
      if (options[:boolean])
        define_method(:"#{name}?") do
          iv_value = instance_variable_get(iv)

          !!(iv_value.nil? ? (self.superclass.respond_to?(name) ? self.superclass.send(name) : nil) : iv_value)
        end
      end

      define_method(name) do
        iv_value = instance_variable_get(iv)
        
        iv_value.nil? ? (self.superclass.respond_to?(name) ? self.superclass.send(name) : nil) : iv_value
      end
    end
  
    define_method(name) do
      iv_value = instance_variable_get(iv)

      iv_value.nil? ? self.class.send(name) : iv_value
    end

    if (options[:boolean])
      define_method(:"#{name}?") do
        iv_value = instance_variable_get(iv)

        !!(iv_value.nil? ? self.class.send(name) : iv_value)
      end
    end
    
    instance_variable_set(iv, options[:default])
  end
end

#option_writer(*names) ⇒ Object

Given a list of names, this declares an option writer which works like a combination of cattr_writer and attr_writer, except that defaults defined for a class will propagate down to the instances and subclasses, but these defaults can be over-ridden in subclasses and instances without interference.



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# File 'lib/pigeon/option_accessor.rb', line 67

def option_writer(*names)
  names = [ names ].flatten.compact
  options = names.last.is_a?(Hash) ? names.pop : { }
  
  names.each do |name|
    iv = :"@#{name}"

    (class << self; self; end).class_eval do
      if (options[:boolean])
        define_method(:"#{name}=") do |value|
          instance_variable_set(iv, value.nil? ? nil : !!value)
        end
      else
        define_method(:"#{name}=") do |value|
          instance_variable_set(iv, value)
        end
      end
    end
  
    if (options[:boolean])
      define_method(:"#{name}=") do |value|
        instance_variable_set(iv, value.nil? ? nil : !!value)
      end
    else
      define_method(:"#{name}=") do |value|
        instance_variable_set(iv, value)
      end
    end
  end
end