Question

我正在尝试将我的项目升级到Rails 4，has_many ..：order =＆gt;已经改变了，所以我很容易重写简单的陈述，如：

has_many :trackbacks, :dependent => :destroy, :order => "created_at ASC"

到

has_many :trackbacks, -> { order 'created_at desc' }, :dependent => :destroy

然而，我一直试图重写：

 has_many :comments,   :dependent => :destroy, :order => "created_at ASC" do
   # Get only ham or presumed_ham comments
  def ham
     where(:state => ["presumed_ham", "ham"])
  end
  # Get only spam or presumed_spam comments
  def spam
     where(:state => ["presumed_spam", "spam"])
  end
end

我试过了：

 has_many :comments -> { order 'position desc' do
 # Get only ham or presumed_ham comments
 def ham
  where(:state => ["presumed_ham", "ham"])
 end
 # Get only spam or presumed_spam comments
 def spam
  where(:state => ["presumed_spam", "spam"])
 end
end
},   :dependent => :destroy

但它不起作用..得到语法错误......可能是正确的语法

    app/models/article.rb:53: syntax error, unexpected ->, expecting keyword_end
   app/models/article.rb:63: syntax error, unexpected ',', expecting keyword_end
     app/models/article.rb:96: syntax error, unexpected keyword_do_block, expecting =>
     app/models/article.rb:97: syntax error, unexpected tSYMBEG, expecting keyword_end
     app/models/article.rb:97: syntax error, unexpected ',', expecting keyword_end
     app/models/article.rb:98: syntax error, unexpected '\n', expecting =>
     app/models/article.rb:99: syntax error, unexpected '\n', expecting =>
     app/models/article.rb:103: syntax error, unexpected '}', expecting =>
     app/models/article.rb:107: syntax error, unexpected ',', expecting =>
     app/models/article.rb:109: syntax error, unexpected '}', expecting =>
     app/models/article.rb:110: syntax error, unexpected '}', expecting =>
     app/models/article.rb:111: syntax error, unexpected '}', expecting =>
     app/models/article.rb:291: syntax error, unexpected ')', expecting =>
     app/models/article.rb:295: syntax error, unexpected ')', expecting =>
     app/models/article.rb:531: syntax error, unexpected end-of-input, expecting keyword_end
     app/controllers/application_controller.rb:42:in `get_latest_published_articles'
     config/initializers/quiet_assets.rb:6:in `call_with_quiet_assets'

Answer 1

你可以尝试一下：

has_many :comments,   :dependent => :destroy, -> {where(:state => ["presumed_ham", "ham"]).order("created_at ASC")}

在Rails4中重写模型顺序范围，正确的语法是什么？

1 个答案: