gistfile1.rb

class PostsController
  def index
    @posts = Post.fetch_all
  rescue Post::FetchError
    redirect_to root_url
  end
  
  def recent
    @posts = Post.fetch_recent
    render 'index'
  rescue Post::FetchError
    redirect_to :back
  end
end

# VS

class PostsController
  # Since the error happens in template rendering, have to use `rescue_from`
  # This results in a loss of context, IMO
  rescue_from Post::FetchError do
    case action_name
    when 'index'
      redirect_to root_url
    when 'recent'
      redirect_to :back
    end
  end
  
  def index
    respond_with ViewModel::Posts.new
  end
  
  def recent
    # Would render the "index" template, somehow
    respond_with ViewModel::RecentPosts.new
  end
end

class ViewModel::Posts
  def posts
    Post.fetch_all
  end
end

class ViewModel::RecentPosts
  def posts
    Post.fetch_recent
  end
end