在db / migrate / … create_slots.rb中:
t.references :slottable, :polymorphic => true
在app / models / slot.rb中:
belongs_to :slottable, :polymorphic => true
在app / models / configuration.rb中:
has_many :slots, :as => :slottable
在rails控制台中,我得到:
ruby-1.9.2-p180 :009 > Slot.last => #<Slot id: 69, slottable_id: 35, slottable_type: "configuration", number: 2, usage: "1GB 667MHz DDR2 SDRAM PC2-5300 SO-DIMM", created_at: "2011-08-09 12:12:25", updated_at: "2011-08-09 12:12:25"> ruby-1.9.2-p180 :009 > Slot.last.slottable NameError: wrong constant name configuration
我能想到的唯一解释是我误解了slottable_type列的使用.我有没有?
目前,在app / models / configuration.rb中:
slot = Slot.find_or_create_by_slottable_id_and_slottable_type(self.id, "configuration")