如何添加'：include_blank =＆gt;真的'到自定义select_tag？

Question

我想添加此选项

  

：include_blank =＆gt;真

如何将其添加到此select_tag？

 <%= select_tag :genre, options_for_select(Genre.all.map{ |g| [g.name, g.id] }) %>

Answer 1

我在文档中找到了这个：

select_tag "people", options_from_collection_for_select(@people, "id", "name"), :prompt => "Select something"

所以你使用：prompt =＆gt; “空白提示”

你的看起来可能是这样的：

select_tag :genre, options_from_collection_for_select(Genre.all.map{ |g| [g.name, g.id] }, "id", "name"), :prompt => "Select something"

此处的文档：http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html 看看select_tag

Answer 2

您可以将选项include_blank与select_tag一起使用。

来自文档：

select_tag "people", options_from_collection_for_select(@people, "id", "name"), :include_blank => true

# => <select id="people" name="people"><option value=""></option><option value="1">David</option></select>

或者您可以使用options_for_select：

<%= select_tag column.name, options_for_select(Genre.all.map{ |g| [g.name, g.id] }), :include_blank => true %>