How to access parent attributes via single table inheritance?

Question

I'm using STI for a project where I'd like each model to have a method that returns a hash. That hash is a specific profile for that model. I'd like each child model to retrieve its parent's hash and add it to its own. Here's an example below

class Shape
 include Mongoid::Document
 field :x, type: Integer
 field :y, type: Integer
 embedded_in :canvas

 def profile
   { properties: {21} }
 end
end



class Rectangle < Shape
 field :width, type: Float
 field :height, type: Float

 def profile
   super.merge({ location: {32} })
 end
end

I'm trying to figure out how to get Rectangle's profile method to return Shape's + its own. It should result in

(properties => 21, location => 32)

Any idea how to access the parent from the inherited child? Is it just super? Been stuck on this for the last couple days. Any help much appreciated!

Answer 1

Yes, it's that simple. :-) You've just got a couple of improper literals in {21} and {32}.

The following works:

class Shape

 def profile
   { properties: 21 }
 end
end


class Rectangle < Shape

 def profile
   super.merge({ location: 32 })
 end
end

rect = Rectangle.new
puts rect.profile # => {:properties => 21, :location => 32}