Question

我有以下mongoid模型，带有范围验证以防止对一张账单进行多次投票。每个投票属于用户和组：

class Vote
  include Mongoid::Document
  field :value, :type => Symbol # can be :aye, :nay, :abstain
  field :type, :type => Symbol  # TODO can delete?

  belongs_to :user
  belongs_to :polco_group

  embedded_in :bill
  validates_uniqueness_of :value, :scope => [:polco_group_id, :user_id, :type]

end

用户可以使用以下方法向帐单添加投票：

  def vote_on(bill, value)    
    if my_groups = self.polco_groups # test to make sure the user is a member of a group
      my_groups.each do |g|
          # TODO see if already voted
          bill.votes.create(:value => value, :user_id => self.id, :polco_group_id => g.id, :type => g.type)
      end
    else
      raise "no polco_groups for this user" # #{self.full_name}"
    end
  end

和一个嵌入许多人的比尔课：投票。这旨在允许用户将他们的投票与不同的组（“Ruby Coders”，“Women”等）相关联并且运行良好，除了数据库当前允许用户在一个账单上多次投票。我怎样才能使以下工作？

u = User.last
b = Bill.last
u.vote_on(b,:nay)
u.vote_on(b,:nay) -> should return a validation error

Answer 1

Vote上的大多数验证器都不会被解雇。您可以通过添加验证功能并输出内容或在其中引发异常来确认。

class Vote
  validate :dummy_validator_to_confirmation

  def dummy_validator_to_confirmation
    raise "What the hell, it is being called, then why my validations are not working?"
  end
end

如果在创建上述验证后User#vote_on未引发异常，则会确认不会通过Vote方法触发vote_on的回调。您需要更改代码以在Vote上触发回调。可能将其改为类似以下内容会有所帮助：

def vote_on(bill, value)    
  if my_groups = self.polco_groups # test to make sure the user is a member of a group
    my_groups.each do |g|
        # TODO see if already voted
        vote = bill.votes.new(:value => value, :user_id => self.id, :polco_group_id => g.id, :type => g.type)
        vote.save
    end
  else
    raise "no polco_groups for this user" # #{self.full_name}"
  end
end

mongoid github问题跟踪器上有一个open issue，允许级联回调嵌入文档。现在回调仅针对正在进行持久性操作的文档触发。

具有范围和belongs_to的Mongoid验证唯一性

1 个答案: