05 Oct 2022   rails


ActionController::Base has a default flash types of [:notice] allowing you to pass a key to #redirect_to:

class Controller < ActionController::Base
  def create
    if true
      redirect_to root_path, status: :see_other, notice: "Created"
    else
      flash[:error] = "Could not create"
      redirect_to root_path, status: :see_other
    end
  end

However, you can add :error as a custom type to get the convenience argument:

class Controller < ActionController::Base
  add_flash_types :error

  def create
    if true
      redirect_to root_path, status: :see_other, notice: "Created"
    else
      redirect_to root_path, status: :see_other, error: "Could not create"
    end
  end