Question

我的模型中有这个：

LOCATION_IN_UK = {'England' => [['Berkshire', 1],['Cambridgeshire',2],['Cheshire',3]], 'Scotland' => [['Dumfries and Galloway',4],['Fife',5],['Lothian',6]], 'Others' => [['Outside UK',7]]}

这是在视图中：

<%= select_tag :location, grouped_options_for_select(Location::LOCATION_IN_UK), :id => 'location-dropdown' %>

此代码生成以下html：

<select id="location-dropdown" name="location">
  <optgroup label="England">
    <option value="1">Berkshire</option> 
    <option value="2">Cambridgeshire</option> 
    <option value="3">Cheshire</option></optgroup>
  <optgroup label="Others">
    <option value="7">Outside UK</option></optgroup>
  <optgroup label="Scotland">
    <option value="4">Dumfries and Galloway</option> 
    <option value="5">Fife</option> 
    <option value="6">Lothian</option></optgroup>
</select>

1. 如何跳过按字母顺序排序的顺序。我希望元素的位置与哈希LOCATION_IN_UK完全相同 2. 如何在此处插入提示？ :prompt => 'Please select'不起作用

Answer 1

要回答提示问题，提示不是哈希，它是方法调用的第三个参数。所以你会这样做：

 <%= select_tag :location, grouped_options_for_select(LOCATIONS_IN_UK, nil, "Please Select"), :id => 'location-dropdown' %>

查看源代码，似乎没有办法跳过排序。你可以编写自己的帮助方法。这是来源

# File actionpack/lib/action_view/helpers/form_options_helper.rb, line 449
      def grouped_options_for_select(grouped_options, selected_key = nil, prompt = nil)
        body = ''
        body << content_tag(:option, prompt, { :value => "" }, true) if prompt

        grouped_options = grouped_options.sort if grouped_options.is_a?(Hash)

        grouped_options.each do |group|
          body << content_tag(:optgroup, options_for_select(group[1], selected_key), :label => group[0])
        end

        body.html_safe
      end

您可以修改/覆盖该方法，但如果您在其他地方使用此功能，则可能会中断，这就是为什么我建议您将以下内容放在application_helper中。

def unsorted_grouped_options_for_select(grouped_options, selected_key = nil, prompt = nil)
  body = ''
  body << content_tag(:option, prompt, { :value => "" }, true) if prompt

  ##Remove sort
  #grouped_options = grouped_options.sort if grouped_options.is_a?(Hash)

  grouped_options.each do |group|
    body << content_tag(:optgroup, options_for_select(group[1], selected_key), :label => group[0])
  end

  body.html_safe
end

然后你可以调用unsorted_grouped_options_for_select它应该可以工作。

 <%= select_tag :location, unsorted_grouped_options_for_select(LOCATION::LOCATION_IN_UK, nil, "Please Select"), :id => 'location-dropdown' %>

Answer 2

我遇到了同样的问题。你可以通过使用数组版本而不是哈希来解决这个问题，因为只有它是is_a？（哈希）它才会命令它。请参阅文档格式：http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/grouped_options_for_select

select_tag helper with grouped_options_for_select order

2 个答案: