Mongoid驗證唯一性與範圍和belongs_to

Question

我有以下mongoid模型，範圍驗證，以防止在一個賬單上的多個選票。每票屬於用戶和組：

 
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 

用戶有以下方法進行了表決添加到賬單：

 
    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 

和嵌入許多法案類：票。這樣做的目的是允許用戶將他們的投票與不同的團體（「Ruby編碼」，「女性」等）相關聯，並且運行良好，除了數據庫目前允許用戶在一張賬單上多次投票。我如何獲得以下功能？

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

Answer 1

最有可能的驗證器上Vote不會被解僱。您可以通過添加驗證功能並輸出內容或引發異常來確認。

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 

如果創建上述的驗證User#vote_on不會引發異常後，就已經證實回調不通過vote_on方法燒製Vote。您需要更改您的代碼以觸發Vote上的回調。也許改變它類似於以下，將有助於：

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 

上有mongoid GitHub上的問題跟蹤，使級聯回調到嵌入文檔的。現在回調只能在正在發生持久性操作的文檔上觸發。