ruby - relation has_many rails with inheritance -

I have:

  class character & lt; ActiveRecord :: Base is: Medium: Item, By: character_items has_many: character_item end class item & lt; ActiveRecord :: Base Class Weapons & lt; Item class armor & lt; Item   
 I have to implant:  
 myCharacter.weapons  
  is_maya: via weapon, :: character_items  Not working, I want the same thing as the item, but only to get the "weapon" items I want to filter with the "Type" column.  
 Thx for help  
 PS: I am on Rail 4   
 
 is_many: via weapon, :: character_items, terms: {character_items: {type: "weapon"}}, class_name: "item", source :: item   
 Hope  
   Answers from the matrix:  Helps answer:  
  is_maya: arms, {Via: character_ts, source :: items}, - & gt; {Where (type: 'weapon')}