Ruby-on-rails 在模型中使用助手：如何包含助手依赖项？
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Using helpers in model: how do I include helper dependencies?
提问by O. Frabjous-Dey
I'm writing a model that handles user input from a text area. Following the advice from http://blog.caboo.se/articles/2008/8/25/sanitize-your-users-html-input, I'm cleaning up the input in the model before saving to database, using the before_validate callback.
我正在编写一个模型来处理来自文本区域的用户输入。按照http://blog.caboo.se/articles/2008/8/25/sanitize-your-users-html-input的建议，我在保存到数据库之前清理模型中的输入，使用 before_validate打回来。
The relevant parts of my model look like this:
我的模型的相关部分如下所示：
include ActionView::Helpers::SanitizeHelper
class Post < ActiveRecord::Base {
before_validation :clean_input
...
protected
def clean_input
self.input = sanitize(self.input, :tags => %w(b i u))
end
end
Needless to say, this doesn't work. I get the following error when I try and save a new Post.
不用说，这行不通。当我尝试保存新帖子时出现以下错误。
undefined method `white_list_sanitizer' for #<Class:0xdeadbeef>
Apparently, SanitizeHelper creates an instance of HTML::WhiteListSanitizer, but when I mix it into my model it can't find HTML::WhiteListSanitizer. Why? What can I do about this to fix it?
显然，SanitizeHelper 创建了一个 HTML::WhiteListSanitizer 实例，但是当我将它混合到我的模型中时，它找不到 HTML::WhiteListSanitizer。为什么？我能做些什么来解决这个问题？
回答by lornc
This gives you just the helper method without the side effects of loading every ActionView::Helpers method into your model:
这为您提供了辅助方法，而没有将每个 ActionView::Helpers 方法加载到模型中的副作用：
ActionController::Base.helpers.sanitize(str)
回答by Alfreddd
Just change the first line as follows :
只需按如下方式更改第一行：
include ActionView::Helpers
that will make it works.
这将使它起作用。
UPDATE:For Rails 3 use:
更新：对于 Rails 3 使用：
ActionController::Base.helpers.sanitize(str)
Credit goes to lornc's answer
幸得lornc的答案
回答by skozz
This works better for me:
这对我来说效果更好：
Simple:
简单的：
ApplicationController.helpers.my_helper_method
Advance:
进步：
class HelperProxy < ActionView::Base
include ApplicationController.master_helper_module
def current_user
#let helpers act like we're a guest
nil
end
def self.instance
@instance ||= new
end
end
Source: http://makandracards.com/makandra/1307-how-to-use-helper-methods-inside-a-model
资料来源：http: //makandracards.com/makandra/1307-how-to-use-helper-methods-inside-a-model
回答by Tarmo
To access helpers from your own controllers, just use:
要从您自己的控制器访问助手，只需使用：
OrdersController.helpers.order_number(@order)
回答by axsuul
I wouldn't recommend any of these methods. Instead, put it within its own namespace.
我不会推荐任何这些方法。相反，将它放在自己的命名空间中。
class Post < ActiveRecord::Base
def clean_input
self.input = Helpers.sanitize(self.input, :tags => %w(b i u))
end
module Helpers
extend ActionView::Helpers::SanitizeHelper
end
end
回答by Atchyut Nagabhairava
If you want to use a the my_helper_methodinside a model, you can write:
如果要my_helper_method在模型内部使用，可以这样写：
ApplicationController.helpers.my_helper_method
