How do I manage multiple lists? This is what I need. Sometimes an item needs to be moved from one list to another. class Item < ActiveRecord::Base belongs_to :group acts_as_list :scope => :group end class Group < ActiveRecord::Base has_many :items, :order => "position" end Now, sometimes, I may need to change an item from one group to another. But when I do that, the position number is not corrected. I end up having multiple items in a group with the same position. What is the correct way to handle something like this? Thanks for your help. Arpan
on 2006-03-23 20:08
on 2006-04-02 14:04
I've had the same problem. It seems that acts_as_list doesn't updates positions when scope changes. I tried to set up a callback method before_validation_on_update in the model, like so : class Item < ActiveRecord::Base belongs_to :group acts_as_list :scope => :group before_validation_on_update :reorder_positions private def reorder_positions @updated_group_id = params[:person][:group_id] unless @updated_group_id == self.group_id self.move_to_bottom # reorder original list params[:item][:position] = Group.find_by_id(@updated_group_id).items.length + 1 end end end Unfortunately it doesn't work, somehow the model throws an error on accessing the params hash. So I solved this at the controller level, in the update method. It works but I'm concerned about breaking the MVC, such a reordering should happen in the model. Bernard.