partial_path

# File actionpack/lib/action_view/renderer/partial_renderer.rb, line 366
    def partial_path(object = @object)
      object = object.to_model if object.respond_to?(:to_model)

      path = if object.respond_to?(:to_partial_path)
        object.to_partial_path
      else
        klass = object.class
        if klass.respond_to?(:model_name)
          ActiveSupport::Deprecation.warn "ActiveModel-compatible objects whose classes return a #model_name that responds to #partial_path are deprecated. Please respond to #to_partial_path directly instead."
          klass.model_name.partial_path
        else
          raise ArgumentError.new("'#{object.inspect}' is not an ActiveModel-compatible object that returns a valid partial path.")
        end
      end

      @partial_names[path] ||= merge_prefix_into_object_path(@context_prefix, path.dup)
    end