Mongoid::RelationsDirtyTracking

Mongoid extension for tracking changes on document relations.

Installation

Add this line to your application's Gemfile:

gem 'mongoid_relations_dirty_tracking'

Version Support

This gem is CI tested using:

Rails 5.1, 5.2, and 6.0
Mongoid 7.0 and 7.1

Usage

class SampleDocument
  include Mongoid::Document
  include Mongoid::RelationsDirtyTracking

  embeds_one  :foo
  has_many    :bars

  field :title, type: String
end

doc = SampleDocument.create
doc.foo = Foo.new(title: 'foo')
doc.bars << Bar.new(title: 'bar')
doc.title = 'New title'

doc.relations_changed?      # => true
doc.relation_changes        # => {"foo" => [nil, {"_id"=>"524c35ad1ac1c23084000040", "title" => "foo"}], "bars" => [nil, [{"_id"=>"524c35ad1ac1c23084000083"}]]}
doc.changed_with_relations? # => true
doc.changes_with_relations  # => {"title" => [nil, "New title"], "foo" => [nil, {"_id"=>"524c35ad1ac1c23084000040", "title" => "foo"}], "bars" => [nil, [{"_id"=>"524c35ad1ac1c23084000083"}]]}

doc.save
doc.relations_changed?      # => false
doc.relation_changes        # => {}
doc.changed_with_relations? # => false
doc.changes_with_relations  # => {}

Disablement

Relations dirty tracking can be resource intensive, hence you may wish to disable it dynamically.

When using .only?

If you query objects with the .only?(*fields) modifier, Mongoid itself marks the objects as readonly and attempts to save them will fail. In this case, relations dirty tracking is automatically disabled.

Mongoid::RelationsDirtyTracking.disable do
  doc = SampleDocument.all.only(:title).first
  doc.foo = Foo.new(title: 'foo')
  doc.bars << Bar.new(title: 'bar')

  doc.relations_changed? # => false
  doc.relation_changes   # => {}
 
  doc.save! #=> raises Mongoid::Errors::ReadonlyDocument
end

Within a block scope

You may disable relations dirty tracking for a given block. This is thread-safe and will use the RequestStore gem if it is included in your project.

Mongoid::RelationsDirtyTracking.disable do
  doc = SampleDocument.create
  doc.foo = Foo.new(title: 'foo')
  doc.bars << Bar.new(title: 'bar')

  doc.relations_changed? # => false
  doc.relation_changes   # => {}
end

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request

Attribution

Created 2013 by David Sevcik

Maintenance from 2020 onward provided by TableCheck