Class: SimpleFacade::Linking::LinkingObserver

Inherits:
Object
  • Object
show all
Defined in:
lib/simple_facade/linking.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reader = nil) ⇒ LinkingObserver

Returns a new instance of LinkingObserver.



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# File 'lib/simple_facade/linking.rb', line 11

def initialize(reader = nil)
  @reader = reader
end

Instance Attribute Details

#current_object ⇒ Object (readonly)

Returns the value of attribute current_object.



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# File 'lib/simple_facade/linking.rb', line 9

def current_object
  @current_object
end

#previous_step ⇒ Object (readonly)

Returns the value of attribute previous_step.



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# File 'lib/simple_facade/linking.rb', line 9

def previous_step
  @previous_step
end

#reader ⇒ Object (readonly)

Returns the value of attribute reader.



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# File 'lib/simple_facade/linking.rb', line 9

def reader
  @reader
end

Instance Method Details

#direct? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/simple_facade/linking.rb', line 27

def direct?
  reader == SimpleFacade::Linking::SUCCESSOR
end

#double? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/simple_facade/linking.rb', line 15

def double?
  reader.nil?
end

#link(current_object, next_object, predecessor, successor) ⇒ Object 



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# File 'lib/simple_facade/linking.rb', line 36

def link(current_object, next_object, predecessor, successor)
  return next_object if predecessor.nil? || current_object.nil?

  link_predecessor(current_object, next_object, predecessor)
  link_successor(current_object, next_object, successor)

  next_object
end

#link_predecessor(current_object, next_object, predecessor) ⇒ Object 



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# File 'lib/simple_facade/linking.rb', line 45

def link_predecessor(current_object, next_object, predecessor)
  return if single? && direct?
  next_object.singleton_class.class_eval do
    attr_accessor :predecessor
  end
  next_object.predecessor = predecessor
  next_object.singleton_class.class_eval do
    attr_accessor next_object.predecessor
  end
  next_object.public_send(:"#{next_object.predecessor}=", current_object)
end

#link_successor(current_object, next_object, successor) ⇒ Object 



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# File 'lib/simple_facade/linking.rb', line 57

def link_successor(current_object, next_object, successor)
  return if single? && reverse?
  current_object.singleton_class.class_eval do
    attr_accessor :successor
  end
  current_object.successor = successor
  current_object.singleton_class.class_eval do
    attr_accessor current_object.successor
  end
  current_object.public_send(:"#{current_object.successor}=", next_object)
end

#on_new_object(accessor, object) ⇒ Object 



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# File 'lib/simple_facade/linking.rb', line 31

def on_new_object(accessor, object)
  @current_object = link(@current_object, object, @previous_step, accessor)
  @previous_step = accessor
end

#reverse? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/simple_facade/linking.rb', line 23

def reverse?
  reader == SimpleFacade::Linking::PREDECESSOR
end

#single? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/simple_facade/linking.rb', line 19

def single?
  !double?
end