ruby-on-rails-3 - collection_select 截断

Question

我如何截断 collection_select 中的值

<%= collection_select(:standard, :parent_id, Standard.all, :id, :value, {:include_blank => 'No Parent'} ) %>

我想缩短该值，但遇到以下错误:

<%= collection_select(:standard, :parent_id, Standard.all, :id, truncate(:value, :length => 40), {:include_blank => 'No Parent'} ) %>

Answer 1

选项 1:

向您的模型添加自定义方法，例如 truncated_value ，并改用它:

class Standard < ActiveRecord::Base
  include ActionView::Helpers::TextHelper

  def truncated_value
    truncate(value, :length => 40)
  end

  ...
  ...
  ...
end

那么在你看来:

<%= collection_select(:standard, 
                      :parent_id, 
                      Standard.all, 
                      :id, 
                      :truncated_value, 
                      {:include_blank => 'No Parent'}) %>

选项 2:

只需使用 select代替标签助手:

<%= select(:standard, 
           :parent_id, 
           Standard.all.collect{ |s| [truncate(s.value, :length => 40), s.id] },
           {:include_blank => 'No Parent'}) %>