javascript - 从 Controller 函数(Ruby on Rails)向选择框添加值

Question

我有一个带有选择框的 Rails 网络应用程序:

<%= select_tag :foo %>

我想在 Controller 中编写一个函数，用一些值填充这个选择框。我需要编写什么代码才能做到这一点？

如果将值硬编码到函数中就没问题。

def populate
  # what goes here?
end

Answer 1

看看options_for_select .它为您要显示的内容构建 html。

  options_for_select([["Dollar", "$"], ["Kroner", "DKK"]])
    <option value="$">Dollar</option>\n<option value="DKK">Kroner</option>

  options_for_select([ "VISA", "MasterCard" ], "MasterCard")
    <option>VISA</option>\n<option selected="selected">MasterCard</option>

  options_for_select({ "Basic" => "$20", "Plus" => "$40" }, "$40")
    <option value="$20">Basic</option>\n<option value="$40" selected="selected">Plus</option>

  options_for_select([ "VISA", "MasterCard", "Discover" ], ["VISA", "Discover"])
    <option selected="selected">VISA</option>\n<option>MasterCard</option>\n<option selected="selected">Discover</option>

您可以像这样将此函数的结果传递给 select_tag:

  <%= select_tag 'company_id', options_for_select(@current_user.active_companies.map { |c| [c.name, c.id] }) %>