Module: ActiveRecord::Acts::List::InstanceMethods

Defined in:
lib/active_record/acts/list.rb

Overview

All the methods available to a record that has had acts_as_list specified. Each method works by assuming the object to be the item in the list, so chapter.move_lower would move that chapter lower in the list of all chapters. Likewise, chapter.first? would return true if that chapter is the first in the list of all chapters.

Instance Method Summary collapse

Instance Method Details

#decrement_position ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 115

def decrement_position
  update_attribute position_column, self.send(position_column).to_i - 1
end

#first? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/acts/list.rb', line 119

def first?
  self.send(position_column) == 1
end

#higher_item ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 127

def higher_item
  self.class.find_first(
    "#{scope_condition} AND #{position_column} = #{(send(position_column).to_i - 1).to_s}"
  )
end

#increment_position ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 111

def increment_position
  update_attribute position_column, self.send(position_column).to_i + 1
end

#last? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/acts/list.rb', line 123

def last?
  self.send(position_column) == bottom_position_in_list
end

#lower_item ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 133

def lower_item
  self.class.find_first(
    "#{scope_condition} AND #{position_column} = #{(send(position_column).to_i + 1).to_s}"
  )
end

#move_higher ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 83

def move_higher
  return unless higher_item

  self.class.transaction do
    higher_item.increment_position
    decrement_position
  end
end

#move_lower ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 74

def move_lower
  return unless lower_item

  self.class.transaction do
    lower_item.decrement_position
    increment_position
  end
end

#move_to_bottom ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 92

def move_to_bottom
  self.class.transaction do
    decrement_positions_on_lower_items
    assume_bottom_position
  end
end

#move_to_top ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 99

def move_to_top
  self.class.transaction do
    increment_positions_on_higher_items
    assume_top_position
  end
end

#remove_from_list ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 106

def remove_from_list
  decrement_positions_on_lower_items
end