Ruby on rails 4 将范围写入rails 4.0模型

我正在使用rails 4.0开发应用程序。我的博客控制器中有此代码

@published = params[:published]

@blogs = Blog.published_blogs.where('published >= ? AND published <= ?', (params[:published].to_date).beginning_of_month, (params[:published].to_date).end_of_month)   

然后把我的控制器换成了

@blogs = Blog.published_blogs.by_published(params[:published])

---

在Rails 4中，作用域再次发生了变化——这就是为什么我对使用它们感到不安的原因：

scope :by_published, ->(published) { where('published >= ? AND published <= ?', (published).to_date.beginning_of_month ,(published).to_date.end_of_month if published.present?)}

scope :by_published, ->(published) { where('published >= ? AND published <= ?', (published).to_date.beginning_of_month ,(published).to_date.end_of_month if published.present?)}

class Article < ActiveRecord::Base
  scope :created_before, ->(time) { where("created_at < ?", time) }
end

class Article < ActiveRecord::Base
  def self.created_before(time)
    where("created_at < ?", time)
  end
end

category.articles.created_before(time)