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 118

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 122

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

#higher_item ⇒ Object 



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# File 'lib/active_record/acts/list.rb', line 130

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 114

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

#insert_at(position = 1) ⇒ Object 



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

def insert_at(position = 1)
  position == 1 ? add_to_list_top : insert_at_position(position)
end

#last? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/acts/list.rb', line 126

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 136

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 87

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 78

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 96

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 103

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 110

def remove_from_list
  decrement_positions_on_lower_items
end