Instance variable visibility on callback method

[knightq]

In my use case I need to factor rendering logic whose behaviour is conditioned by some values computed on the action:

class StatisticsController < ApplicationController
  before_render :choose_render
  def my_custom_action
    ...
    @records = <something>
    .,.
  end
  ...
  def choose_render
     if @records.first # here is an exception (@records is nil)...
     ...
  end
end

but it is not possible, since @records is not available in the context of the callback function choose_render.