Setting values other then from form on create

feedbacks_controller.rb

def create
  @feedback = Feedback.new(feedback_params)
  respond_to do |format|
    if @feedback.save
      if current_user
        @feedback.created_by = current_user.id
        format.html { redirect_to user_path(current_user), notice: "Tack för din feedback!"}
      end
      format.html { redirect_to root_path, notice: "Tack för din feedback!"}
    else
      format.html { render :new }
    end
  end
end

def destroy
  @feedback.destroy
  redirect_to root_path
end

private

def feedback_params
  params.require(:feedback).permit(:subject,:body)
end