Ruby on rails - grouped_options_for_select顺序的select_tag助手

Question

我在我的模型中有这个:

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

在视图中:

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

代码生成如下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。如何跳过字母排序顺序。我希望元素的位置与散列LOCATION_IN_UK中的位置完全相同。
2。如何在此插入提示符?:prompt => 'Please select'不工作

Answer 1

回答您的提示问题，提示不是一个散列，它是方法调用的第三个参数。你可以这样写:

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

看源代码，似乎没有办法跳过排序。不过，您可以编写自己的helper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函数，则可能会中断，这就是为什么我建议您在application_helper中放入以下内容。

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

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

我也遇到了同样的问题。你可以通过使用数组版本而不是哈希来解决这个问题，因为它只在它是_a?(哈希)时才排序。请参阅文档获取格式:http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/grouped_options_for_select