retrospring/app/controllers/question_controller.rb

class QuestionController < ApplicationController
  def show
    @question = Question.find(params[:id])
    @answers = @question.cursored_answers(last_id: params[:last_id])
    @answers_last_id = @answers.map(&:id).min
    @more_data_available = !@question.cursored_answers(last_id: @answers_last_id, size: 1).count.zero?

    respond_to do |format|
      format.html
      format.js
    end
  end
end