Ruby on Rails 4 选择多个

Question

我有一个创建新用户的表单。我正在尝试添加一个下拉选项来选择权限级别。我希望能够为每个用户选择多个权限级别。

这是我的看法，我加了{:multiple => true}：

<%= f.label :permission, "Permission Level" %>
<%= f.select :permission, [ ["Read Only", "read"], ["IP Voice Telephony", "ip_voice"], ["IP Video Telephony", "ip_video_telephony"], ["Enterprise Gateways", "enterprise_gateways"], ["Consumer ATAs", "consumer_atas"], ["IP PBX", "ip_pbx"], ["Master of All", "all"] ], {prompt: "Select Permission Level"}, {:multiple => true}, class: "input-lg" %>

我的控制器，我添加了:permission => []：

def user_params
  params.require(:user).permit(:name, :email, :password, :password_confirmation, :admin, :permission => [])
end

我的视图出现的错误 f.select：

wrong number of arguments (5 for 2..4)

如何为 Rails 4 选择多重选择？

Answer 1

class 和 multiple 都是 html_options 的一部分，因此它们应该放在一个哈希中。

改变

<%= f.select :permission, [ ["Read Only", "read"], ["IP Voice Telephony", "ip_voice"], ["IP Video Telephony", "ip_video_telephony"], ["Enterprise Gateways", "enterprise_gateways"], ["Consumer ATAs", "consumer_atas"], ["IP PBX", "ip_pbx"], ["Master of All", "all"] ], {prompt: "Select Permission Level"},
{:multiple => true}, class: "input-lg" %>

到

<%= f.select :permission, [ ["Read Only", "read"], ["IP Voice Telephony", "ip_voice"], ["IP Video Telephony", "ip_video_telephony"], ["Enterprise Gateways", "enterprise_gateways"], ["Consumer ATAs", "consumer_atas"], ["IP PBX", "ip_pbx"], ["Master of All", "all"] ], {prompt: "Select Permission Level"},
{:multiple => true, class: "input-lg"} %>

现在您分别传递它们。因此，select 方法的参数计数在应该为 4 时变为 5。因此，错误。

Answer 2

您的 :class 选项不在 html_options 的哈希中：

{:multiple => true}, class: "input-lg"

应该是

{:multiple => true, class: "input-lg"}

Answer 3

到目前为止我还没有对其进行测试，但是错误消息非常简单，您正在尝试使用 5 个参数来使用 #select 方法，并且它最多接受 4 个参数，阅读 API 似乎您应该提供'class' 属性在您提供的 'multiple' 相同的哈希中，因为它们都是 html_options。

尝试像这样使用它：

<%= f.select :permission,
             [ ["Read Only", "read"],
               ["IP Voice Telephony", "ip_voice"],
               ["IP Video Telephony", "ip_video_telephony"],
               ["Enterprise Gateways", "enterprise_gateways"],
               ["Consumer ATAs", "consumer_atas"],
               ["IP PBX", "ip_pbx"],
               ["Master of All", "all"] ],
             {prompt: "Select Permission Level"},
             {multiple: true, class: "input-lg"} %>

将权限数组解耦到另一个地方也很好。也许它会有助于维护。

http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-select