update_positions.rb

update_positions.rb

#PagesController
def update
  @page = current_account.pages.find(params[:id], :readonly => false)
  @page.update_attributes(params[:page])
end

#Page
before_update :change_positions, :if => :position_changed?

def change_positions
  # Update position of all other pages
  if position_was < self.position
    a = position_was
    b = self.position
  else
    a = self.position
    b = position_was
  end
  pages = account.pages.where(:id.not_eq => id_was,
                                      :parent_id => parent_id_was,
                                      :position => a..b)#.order(:position)

  pages.each do |page|
    page.update_attribute(:position, page.position + 1) if a == self.position
    page.update_attribute(:position, page.position - 1) if a == position_was
  end
end