活动脚手架

If you want to customize the presentation of a column, you can define a specially named method in your helper file. The format is #{column_name}_column. So, for example, to customize the :username column displayed on your UsersController, you would add a :username_column method to your UsersHelper file.

如果想定制一个字段的显示方式，你可以在帮助文件中定义一个特别命名的方法。格式是 #{column_name}_column. 所以，举例来说，为了定制使字段 :username 在UsersController中显示，需要在 UsersHelper 文件中添加一个 :username_column 方法。

This override method accepts one argument: the entire record object. It is your responsibility to retrieve the interesting value from the record and to clean the value with h().

这个覆盖方法接受一个参数(argument)：整个记录对象。你的职责是，从记录中找回有趣的值并且用 h()清洁这个值。

This override method is used by List and Show.

这个覆盖方法用于列表和显示。

示例:

class User < ActiveRecord::Base
  has_many :roles
end    

module UserHelper
  # joins the first three roles with a hyphen instead of the normal comma.
  # ok, so this one isn't very original.
  def roles_column(record)
    record.roles.first(3).collect{|role| h(role)}.join(' - ')
  end    

  # creates a popup link to the associated division (belongs_to association)
  def division_column(record)
    link_to(h(record.division.name), :action => :show, :controller => 'divisions', :id => record.division.id)
  end
end