Stop_create除非。首先

Question

下午

我有以下代碼停止多個片段的製作如果不認可，但自從我創建的第一個片段沒有什麼參考等我怎麼會寫這將是一些幫助很有用。

validate :stop_create, :on => :create 

    def stop_create 
     errors.add(:base, "could not add due to last snippet not approved") if self.last.approved == false 
end 

Answer 1

檢查在試圖獲取其狀態之前是否確實存在最後一個片段。

def stop_create 
    errors.add(:base, "could not add due to last snippet not approved") if Snippet.last && Snippet.last.approved == false 
end 

OR

def stop_create 
    errors.add(:base, "could not add due to last snippet not approved") if Snippet.last.try(:approved) == false 
end