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

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

Instance Method Summary collapse

Instance Method Details

#decrement_position ⇒ Object

Decrease the position of this item without adjusting the rest of the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 146

def decrement_position
  return unless in_list?
  set_list_position(self.send(position_column).to_i - 1)
end

#default_position ⇒ Object 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 206

def default_position
  acts_as_list_class.columns_hash[position_column.to_s].default
end

#default_position? ⇒ Boolean 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 210

def default_position?
  default_position && default_position.to_i == send(position_column)
end

#first? ⇒ Boolean 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 151

def first?
  return false unless in_list?
  !higher_items(1).exists?
end

#higher_item ⇒ Object

Return the next higher item in the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 162

def higher_item
  return nil unless in_list?
  higher_items(1).first
end

#higher_items(limit = nil) ⇒ Object

Return the next n higher items in the list selects all higher items by default



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 169

def higher_items(limit=nil)
  limit ||= acts_as_list_list.count
  position_value = send(position_column)
  acts_as_list_list.
    where("#{quoted_position_column_with_table_name} <= ?", position_value).
    where("#{quoted_table_name}.#{self.class.primary_key} != ?", self.send(self.class.primary_key)).
    reorder(acts_as_list_order_argument(:desc)).
    limit(limit)
end

#in_list? ⇒ Boolean

Test if this record is in a list



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 198

def in_list?
  !not_in_list?
end

#increment_position ⇒ Object

Increase the position of this item without adjusting the rest of the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 140

def increment_position
  return unless in_list?
  set_list_position(self.send(position_column).to_i + 1)
end

#insert_at(position = acts_as_list_top) ⇒ Object

Insert the item at the given position (defaults to the top position of 1).



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 68

def insert_at(position = acts_as_list_top)
  insert_at_position(position)
end

#insert_at!(position = acts_as_list_top) ⇒ Object 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 72

def insert_at!(position = acts_as_list_top)
  insert_at_position(position, true)
end

#last? ⇒ Boolean 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 156

def last?
  return false unless in_list?
  !lower_items(1).exists?
end

#lower_item ⇒ Object

Return the next lower item in the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 180

def lower_item
  return nil unless in_list?
  lower_items(1).first
end

#lower_items(limit = nil) ⇒ Object

Return the next n lower items in the list selects all lower items by default



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 187

def lower_items(limit=nil)
  limit ||= acts_as_list_list.count
  position_value = send(position_column)
  acts_as_list_list.
    where("#{quoted_position_column_with_table_name} >= ?", position_value).
    where("#{quoted_table_name}.#{self.class.primary_key} != ?", self.send(self.class.primary_key)).
    reorder(acts_as_list_order_argument(:asc)).
    limit(limit)
end

#move_higher ⇒ Object

Swap positions with the next higher item, if one exists.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 91

def move_higher
  return unless higher_item

  acts_as_list_class.transaction do
    if higher_item.send(position_column) != self.send(position_column)
      swap_positions(higher_item, self)
    else
      higher_item.increment_position
      decrement_position
    end
  end
end

#move_lower ⇒ Object

Swap positions with the next lower item, if one exists.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 77

def move_lower
  return unless lower_item

  acts_as_list_class.transaction do
    if lower_item.send(position_column) != self.send(position_column)
      swap_positions(lower_item, self)
    else
      lower_item.decrement_position
      increment_position
    end
  end
end

#move_to_bottom ⇒ Object

Move to the bottom of the list. If the item is already in the list, the items below it have their position adjusted accordingly.



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

def move_to_bottom
  return unless in_list?
  acts_as_list_class.transaction do
    decrement_positions_on_lower_items
    assume_bottom_position
  end
end

#move_to_top ⇒ Object

Move to the top of the list. If the item is already in the list, the items above it have their position adjusted accordingly.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 116

def move_to_top
  return unless in_list?
  acts_as_list_class.transaction do
    increment_positions_on_higher_items
    assume_top_position
  end
end

#move_within_scope(scope_id) ⇒ Object

Move the item within scope. If a position within the new scope isn’t supplied, the item will be appended to the end of the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 134

def move_within_scope(scope_id)
  send("#{scope_name}=", scope_id)
  save!
end

#not_in_list? ⇒ Boolean 



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 202

def not_in_list?
  send(position_column).nil?
end

#remove_from_list ⇒ Object

Removes the item from the list.



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 125

def remove_from_list
  if in_list?
    decrement_positions_on_lower_items
    set_list_position(nil)
  end
end

#set_list_position(new_position, raise_exception_if_save_fails = false) ⇒ Object

Sets the new position and saves it



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# File 'lib/acts_as_list/active_record/acts/list.rb', line 215

def set_list_position(new_position, raise_exception_if_save_fails=false)
  write_attribute position_column, new_position
  raise_exception_if_save_fails ? save! : save
end