我在哪里添加一个类在这个Rails的collection_select？

Question

我无法添加一个类来此collection_select：

<%= f.collection_select :category_id, Category.all, :id, :name, {:prompt => 'Choose a category'}, {:required => true} %> 

我已经试过这样：

<%= f.collection_select :category_id, Category.all, :id, :name, {:prompt => 'Choose a category'}, {:required => true}, {:class => "form_inputs"} %> 

除了这一点：

<%= f.collection_select :category_id, Category.all, :id, :name, {prompt: "Choose a category"}, {required: true}, {class: "form_inputs"} %> 

但无论似乎工作。是什么赋予了？

Answer 1

Try like this 
<%= f.collection_select :category_id, Category.all, :id, :name, {:prompt => 'Choose a category'}, :class => "form_inputs" %> 

Answer 2

试试这个...测试。

<%= f.collection_select 'category_id', Category.all, 'id', 'name', {prompt: "Choose a category"}, class: "form_inputs", required:true %>