DM hook before :save

I've been using DM's hooks a lot to do the customized validation. Today I was trying to set a property before save,

	before :save, :set_order_no
	def set_order_no
	order_no = next_order_no if order_no.nil? || order_no.blank?
	end
	private
	def next_order_no
	...
	end

view raw wont_work.rb hosted with ❤ by GitHub

It won't work.

Finally, I figured it out, use attribute_set

	# dm modle
	class SampleOrder
	include DataMapper::Resource
	property :id, Serial
	property :order_no, String
	...
	before :save, :set_order_no
	def set_order_no
	attribute_set(:order_no, next_order_no) if order_no.nil? || order_no.blank?
	end
	private
	def next_order_no
	...
	end
	end

view raw dm_attribute_set.rb hosted with ❤ by GitHub