在保存时执行覆盖的模型getter？

Question

我目前正在修复Rails插件中的一个bug，我刚刚找到了导致这个问题的方法。我的猜测是，它与它的ActiveRecord类Sprint中覆盖的getter方法之一有某种联系。方法名为burndown，还有一个名为burndown的属性，它存储序列化哈希。

class Sprint < ActiveRecord::Base

  serialize :burndown, Hash
  ...

  def touch!
    ... do stuff ...
    self.burndown = nil
    self.save!
  end

  def burndown
    ... some crazy-ass method ...
  end
end

因此，在保存时会以某种方式执行燃尽方法，但我不太确定为什么，因为没有为Sprint类定义回调。是否有可能是覆盖getter方法导致了这种情况？

Answer 1

即使您没有任何验证或回调，Getter方法在保存时也会被调用。

"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activemodel-3.2.13/lib/active_model/dirty.rb:143:in `attribute_change'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activemodel-3.2.13/lib/active_model/dirty.rb:117:in `block in changes'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activemodel-3.2.13/lib/active_model/dirty.rb:117:in `map'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activemodel-3.2.13/lib/active_model/dirty.rb:117:in `changes'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/attribute_methods/dirty.rb:23:in `save'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:259:in `block (2 levels) in save'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:313:in `block in with_transaction_returning_status'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:208:in `transaction'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:311:in `with_transaction_returning_status'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:259:in `block in save'"
"/home/user/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:270:in `rollback_active_record_state!'"
"/home/usha/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.13/lib/active_record/transactions.rb:258:in `save'"

因此，如果为属性重写getter，请确保它仍然执行其原始功能。