redirects.rb

class PocController
  before_filter :redirect_to_root_url, only: :show4

  def show1
    redirect_to_root_url
    render # => Double render error!!!
  end

  def show2
    redirect_to_root_url
    # => No explicit render, so rails is smart enough to know that a redirect_to has been called and no template is rendered
  end

  def show3
    redirect_to_root_url_returning_true and return
    render # => Never called because of "and return" above
  end

  def show4
    render # => show method is never called as the filter chain is halted (see before_filter above)
  end

  def show5
    # => show5 template is rendered (implicit)
  end

  def show6
    render # => show6 template is rendered (explicit)
  end

  def show7
    render "omg" # => omg template is rendered (explicit)
  end

  private

  def redirect_to_root_url
    redirect_to root_url
  end

  def redirect_to_root_url_returning_true
    redirect_to root_url
    true
  end
end