mongoid - Mongoidの親ドキュメントに埋め込まれたドキュメントのダーティトラッキング

Question

汚れたオブジェクトを追跡する必要がありました。そして、それは親ドキュメントでうまく機能します。しかし、ドキュメントに埋め込まれている、または参照されているものを変更する場合、ドキュメント自体に埋め込まれている/参照されているものを介してダーティにアクセスする必要があります。

親ドキュメント自体のダーティを追跡するにはどうすればよいですか？

Answer 1

I don't think Mongoid's own dirty attributes feature tracks changes to embedded documents. But it's not hard to implement basic dirty tracking of embedded documents yourself with something like this:

class Bar
  include Mongoid::Document
  embeds_many :foos
  attr_accessor :foos_changed
  alias_method :foos_changed?, :foos_changed
  # ...
end

class Foo
  include Mongoid::Document
  embedded_in :bar, :inverse_of => :foos
  after_save :notify_parent
  def notify_parent
    bar.foos_changed = true
  end
  # ...
end

b = Bar.create
b.foos_changed? # => nil
b.foos.create
b.foos_changed? # => true

If you need more options, like including embedded documents changes in Bar.changes or tracking the specific changes, you'll have to override the changes and changed? methods, which I wouldn't do unless you absolutely need those features.

Here's a way to track what changed in the embedded documents:

class Bar
  include Mongoid::Document
  embeds_many :foos
  attr_writer :embedded_changes
  def embedded_changes
    @embedded_changes ||= begin
      self._children.inject({}) do |memo, child|
        memo.merge( 
         {child.collection_name => {child.id => child.changes}} 
        ) if child.changed?
      end
    end
  end

  def changes
    original_value = super
    if original_value.blank?
      embedded_changes
    else
      original_value.merge(embedded_changes)
    end
  end

  def changed?
    super || self._children.any?(&:changed?)
  end
  # ...
end

class Foo
  include Mongoid::Document
  embedded_in :bar, :inverse_of => :foos
  # ...

  field :hat
end

b = Bar.create
f = b.foos.create
b.changes   # => nil 
b.changed?  # => false 
f.hat = 1
f.changes   # => {"hat"=>[nil, "1"]} 
b.changes   # => {"foos"=>{BSON::ObjectId('4cf...')=>{"hat"=>[nil, "1"]}}}    
b.changed?  # => true