ruby-on-rails - 如何在 Ruby 中检查默认单选按钮？

Question

我有一个使用 Ruby 构建的单选按钮，如下所示

      <p>Which design do you prefer to use? </p>
      <% [ 'Design 1', 'Design 2', 'Design 3', 'Design 4', 'Design 5' ].each do |theme| %>
          <br><%= radio_button_tag 'theme', theme, @theme == theme %>
          <%= label_tag "theme_#{theme}", theme.humanize %>
      <% end %>

我想确保默认情况下始终选中第一个元素(也称为设计 1)，除非用户选择其他设计。

Answer 1

您可以这样做:传入 checked检查项目

<%= radio_button_tag 'theme', theme, checked: @theme.FIELD_NAME == 'design' %>

详情请看这里http://apidock.com/rails/ActionView/Helpers/FormTagHelper/radio_button_tag

回复您的评论:

Ahmm I dont understand? :( So <%= radio_button_tag 'theme', theme %>
becomes <%= radio_button_tag 'theme', theme, checked: @theme.FIELD_NAME == 'design' %> ?? But this throws an error? I just want the first radio button element to be selected by default –

FIELD_NAME是模型中列的名称。要只检查第一项，您可以尝试这样做:只需添加 checked: true关键词

<%= radio_button_tag 'theme', theme, @theme == theme, checked: true %>

好的，您需要执行以下操作:

<% [ 'Design 1', 'Design 2', 'Design 3', 'Design 4', 'Design 5' ].each_with_index do |theme, i| %>
  <% if i == 0 %>
      <br><%= radio_button_tag 'theme', theme, @theme == theme, checked: true %>
  <% else %>
      <br><%= radio_button_tag 'theme', theme, @theme == theme %>
  <% end %>
  <%= label_tag "theme_#{theme}", theme.humanize %>
<% end %>