保持named_scope扩展干燥

发布于 2024-08-20 08:24:27 字数 508 浏览 6 评论 0原文

在 Rails 中，您可以在 named_scope 后面添加一个块，用于其他上下文相关的方法，如下所示：

class User < ActiveRecord::Base
  named_scope :inactive, :conditions => {:active => false} do
    def activate
      each { |i| i.update_attribute(:active, true) }
    end
  end
end

在本例中，activate 方法不是在 上定义的。 >User 类，但位于 ActiveRecord::NamedScope::Scope 对象上。

我有一系列的三个范围，需要具有相同的方法定义。为了不重复代码，我如何抽象该块，以便我可以定义它一次并将其传递给每个 named_scope？

原文

In Rails, you can add a block after a named_scope for additional, context-sensitive methods like so:

class User < ActiveRecord::Base
  named_scope :inactive, :conditions => {:active => false} do
    def activate
      each { |i| i.update_attribute(:active, true) }
    end
  end
end

In this example, the activate method is being defined not on the User class, but on the ActiveRecord::NamedScope::Scope object.

I have a series of three scopes that need to have identical method definitions. In the interests of not repeating code, how would I abstract that block such that I could define it once and pass it to each named_scope?

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那小子欠揍 2024-08-27 08:24:27

首先，这是一个很好的问题——我不知道命名作用域的这个特性！以下对我有用：

class User < ActiveRecord::Base
  add_activate = lambda do
    define_method "activate" do
      each { |i| i.update_attribute(:active, true) }
    end
  end

  named_scope :inactive, :conditions => {:active => false}, &add_activate
end

您可以将 add_activate 块作为最后一个参数传递给任何需要 activate 方法的命名范围。

Firstly, great question--I didn't know about that feature of named scopes! The following works for me:

class User < ActiveRecord::Base
  add_activate = lambda do
    define_method "activate" do
      each { |i| i.update_attribute(:active, true) }
    end
  end

  named_scope :inactive, :conditions => {:active => false}, &add_activate
end

You can pass the add_activate block as the last argument to any named scopes that need the activate method.

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滥情空心 2024-08-27 08:24:27

好多了：

http://tuxicity。 se/rails/dry/2009/01/04/share-named-scopes-in-rails.html

module NamedScope
  def self.included(base)
    base.class_eval do
      named_scope :inactive, :conditions => {:active => false} do
        def activate
          each { |i| i.update_attribute(:active, true) }
        end
      end
    end
  end
end

保存在您的 /lib 目录中（在 Rails 3 中的初始化程序中放置一个 require ) 并在您的 User 类中包含 NamedScope

Much better:

http://tuxicity.se/rails/dry/2009/01/04/share-named-scopes-in-rails.html

module NamedScope
  def self.included(base)
    base.class_eval do
      named_scope :inactive, :conditions => {:active => false} do
        def activate
          each { |i| i.update_attribute(:active, true) }
        end
      end
    end
  end
end

Save in your /lib directory (put a require in an initializers in rails 3) and include NamedScope in your User class

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