使用css向属性添加单选按钮的问题

Question

我正在使用html / css模板制作应用程序。当我添加单选按钮时 - 它们看起来效果很好，但在创建模型后 - 所选属性为nil。所有属性都是布尔值，默认为false。

装运控制器：

class ShipmentsController < ApplicationController

  helper_method :shipment, :user
  before_action :set_shipment, only: [:show]
  before_action :authenticate_user!
  before_action :require_same_user, only: [:show]

  def index
    @shipments = Shipment.all
  end

  def new
    @shipment = Shipment.new
  end

  def create
    @shipment = Shipment.new(shipment_params)
    @shipment.user = current_user
    if @shipment.save
      flash[:success] = "Shipment added."
      redirect_to shipment_path(@shipment)
    else
      render 'new'
    end
  end

  def show
    @shipment = Shipment.find(params[:id])
  end

  private

    def user
      @user = current_user
    end

    def shipment
      @shipment = user.shipments.new
    end

    def shipment_params
      params.require(:shipment).permit(:name, :three_days, 
                                       :seven_days, :two_weeks)
    end

    def set_shipment
      @shipment = Shipment.find(params[:id])
    end

    def require_same_user
      if current_user != @shipment.user
        flash[:alert] = "Restricted."
        redirect_to root_path
      end
    end

end

装运表格：

<%= form_for(shipment, html: { multipart: true }) do |f| %>
  <%= f.radio_button :three_days, "3", type: 'radio', name: 'demo-priority' %>
  <%= f.label :three_days, "3 Days", :value => "3" %>

  <%= f.radio_button :seven_days, "7", type: 'radio', name: 'demo-priority' %>
  <%= f.label :seven_days, "7 Days", :value => "7" %>

  <%= f.radio_button :two_weeks, "14", name: 'demo-priority' %>
  <%= f.label :two_weeks, "14 Days", :value => "14" %>
<% end %>

有什么想法吗？