Is there a more efficient way to update the order of a collection of objects in rails 3?

rubyonrails-talk
1

Suppose I have a collection of Pages that are ordered by a column called :sibling_order. Is there a more efficient way to update the ordering of the collection than what I’m doing below:

class Page < ActiveRecord::Base

…

def update_order(order) if (order < self.sibling_order) siblings = Page.where(“parent_id = ? AND sibling_order < ? AND sibling_order >= ?”,new_parent_id,self.sibling_order,order)

siblings.collect{|s|s.update_attribute(:sibling_order,s.sibling_order + 1)}

elsif (order > self.sibling_order) siblings = Page.where(“parent_id = ? AND sibling_order > ? AND sibling_order <= ?”,new_parent_id,self.sibling_order,order)

siblings.collect{|s|s.update_attribute(:sibling_order,s.sibling_order - 1)}

end
self.update_attribute(:sibling_order, order) if self.sibling_order != order
end

…

end

2

Have a look at acts_as_list. Even if you do not want to use it (but why re-invent the wheel) then examining the code may be useful.

Colin