asciinema.org/app/controllers/asciicasts_controller.rb

class AsciicastsController < ApplicationController

  before_filter :load_resource, except: [:index]
  before_filter :ensure_authenticated!, only: [:edit, :update, :destroy]

  respond_to :html, :json

  attr_reader :asciicast

  def index
    render locals: {
      page: BrowsePagePresenter.build(
        policy_scope(Asciicast),
        params[:category],
        params[:order],
        params[:page]
      )
    }
  end

  def show
    respond_to do |format|
      format.html do
        view_counter.increment(asciicast, cookies)
        render locals: {
          page: AsciicastPagePresenter.build(self, asciicast, current_user, params)
        }
      end

      format.json do
        opts = if params[:dl]
          { query: { "response-content-disposition" => "attachment; filename=#{asciicast.download_filename}" } }
               else
                 {}
               end

        redirect_to asciicast.data_url(opts)
      end

      format.png do
        asciicast_image_generator.generate(asciicast) if asciicast.image_stale?
        redirect_to asciicast.image_url
      end
    end
  end

  def example
    render layout: 'example'
  end

  def edit
    authorize asciicast
  end

  def update
    authorize asciicast

    if asciicast_updater.update(asciicast, update_params)
      redirect_to asciicast_path(asciicast),
                  :notice => 'Asciicast was updated.'
    else
      render :edit
    end
  end

  def destroy
    authorize asciicast

    if asciicast.destroy
      redirect_to profile_path(current_user),
                  :notice => 'Asciicast was deleted.'
    else
      redirect_to asciicast_path(asciicast),
                  :alert => "Oops, we couldn't remove this asciicast. " \
                            "Try again later."
    end
  end

  private

  def load_resource
    @asciicast = Asciicast.find_by_id_or_secret_token!(params[:id])
  end

  def view_counter
    @view_counter ||= ViewCounter.new
  end

  def update_params
    params.require(:asciicast).permit(*policy(asciicast).permitted_attributes)
  end

  def asciicast_updater
    AsciicastUpdater.new
  end

  def asciicast_image_generator
    AsciicastImageGenerator.new(self)
  end

end