ruby-on-rails - rails accepts_nested_attributes_for 和验证... Rails 2.3.11

Question

我有两个模型

class Group < AR
  has_many :permissions
  accepts_nested_attributes_for :permissions, :allow_destroy => true
end

class Permission < AR
  validates_uniqueness_of :action, :scope => [:role]
end

我似乎无法在创建新组时获得对工作权限的唯一约束，只能在更新时获得。这是一个示例输出。有谁知道验证嵌套属性和唯一约束的最佳方法吗？

样本输出

> g = Group.create(:permissions_attributes => [{:role => 'admin', :action => 'one'}])
> # Now add the same permissions, should not be valid
> g.permissions_attributes = [{:role => 'admin', :action => 'one'}]
> g.valid?  # => false

这是预期的。但是，如果我使用相同的 permissions_attributes 创建组两次，它不会失效:

> g = Group.new(:permissions_attributes => [{:role => 'admin', :action => 'one'}, {:role => 'admin', :action => 'one'}]
> g.valid?  # => true        BUT THIS SHOULD BE FALSE!!
> g.save # => true           Oh Nos!!!

Answer 1

class Group < AR
  has_many :permissions
  accepts_nested_attributes_for :permissions, :allow_destroy => true
  validates_associated :permissions
end