manage mapping column

In your model,for example in Post,you have a column named status(integer), 1 means normal, 2 means draft, 3 means deleted.

Now,with enum_attr plugin,you just decalre:

enum_attr :status, [ ["正常", 1, "normal"], ["草稿", 2, "draft"], ["已删除", 3, "deleted"] ]

with this declare, you have these code below:

consts:

STATUS_NORMAL = 1; STATUS_DRAFT = 2; STATUS_DELETED = 3
ENUMS_STATUS = [ ["正常", 1], ["草稿", 2], ["已删除", 3] ] # this is for select tag

valitates:

validates_inclusion_of "status", :in => [1,2,3], :allow_nil => true

methods:

# instant_method
def status_name
  # ... return readable status name according to stauts value(integer)
end

更多用法见spec/enum_spec.rb文件

Thanks Quakewang
http://quake.javaeye.com/blog/448235

Copyright © 2010 Qichunren. See LICENSE for details.