Ruby on rails 如何添加'；：包括_blank=>；正确'；要自定义选择_标签？

我想添加这个选项

：include_blank=>true

如何将其添加到此选择标签

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

---

我在文档中找到了：

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

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>

因此使用：prompt=>“blank prompt”

你的可能是这样的：

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：

---

查看选择标签

您可以将选项

包含空白

与

选择标签

一起使用

从文件中：

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

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>