Mongoid 7.3#

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This page describes significant changes and improvements in Mongoid 7.3. The complete list of releases is available on GitHub and in JIRA; please consult GitHub releases for detailed release notes and JIRA for the complete list of issues fixed in each release, including bug fixes.

delete Method Does Not Trigger Association Dependent Behavior#

Breaking change: In Mongoid 7.3, dependent behavior is not invoked when the parent association is deleted using the delete method. For example, after the following code snippet executes, in Mongoid 7.3 the album will remain in the database:

class Band
  include Mongoid::Document

  has_many :albums, dependent: :destroy
end

class Album
  include Mongoid::Document

  belongs_to :band
end

band = Band.create!
album = Album.create!(band: band)

# Does not delete the album from the database
band.delete

Previous versions of Mongoid invoked dependent behavior when deleting parents.

To invoke dependent behavior, use the destroy method:

# Deletes the album from the database
band.destroy

The behavior of Mongoid 7.3 is consistent with how ActiveRecord behaves.

::Boolean Removed#

Breaking change: Mongoid 7.3 removes the global ::Boolean class.

This change should have no impact on classes that simply use Boolean fields, as the Boolean class is aliased from Mongoid::Fields (which is included in Mongoid::Document). The following field definition continues to work in 7.3 as it did in 7.2:

class User
  include Mongoid::Document

  field :verified, type: Boolean
end

However, code that is not executed in the context of a class including Mongoid::Document may need to explicitly qualify Boolean references. The following snippet fails with Mongoid 7.3 due to Boolean being unqualified:

class User
  include Mongoid::Document
end

User.field :verified, type: Boolean

To fix it, use the fully-qualified Mongoid::Boolean class:

User.field :verified, type: Mongoid::Boolean

Note that class_eval is executed in the scope of the caller, not in the scope of the class being modified. Thus even when using class_eval it is necessary to fully qualify Mongoid::Boolean:

User.class_eval do
  field :verified, type: Mongoid::Boolean
end

Additionally, in Mongoid 7.2 ::Boolean and Mongoid::Boolean were different classes. In Mongoid 7.3 there is only one class which is Mongoid::Boolean.

It is possible to restore the global ::Boolean class by executing in your application:

Boolean = Mongoid::Boolean

Note that this aliases Mongoid::Boolean to ::Boolean such that there is still only a single Boolean class:

# With Mongoid 7.3:
Boolean = Mongoid::Boolean
Boolean == Mongoid::Boolean
# => true

# With Mongoid 7.2:
Boolean == Mongoid::Boolean
# => false

Selector Key Stringification#

Minor change: Mongoid now converts symbol keys to string keys in the Criteria selectors. This applies to operators as well as hash literals.

Mongoid 7.3 behavior:

Band.and(year: {'$in': [2020]})
# =>
# #<Mongoid::Criteria
#   selector: {"year"=>{"$in"=>[2020]}}
#   options:  {}
#   class:    Band
#   embedded: false>

Band.where(tag: {city: 1})
# =>
# #<Mongoid::Criteria
#   selector: {"tag"=>{"city"=>1}}
#   options:  {}
#   class:    Band
#   embedded: false>

Mongoid 7.2 behavior:

Band.and(year: {'$in': [2020]})
# =>
# #<Mongoid::Criteria
#   selector: {"year"=>{:$in=>[2020]}}
#   options:  {}
#   class:    Band
#   embedded: false>

Band.where(tag: {city: 1})
# =>
# #<Mongoid::Criteria
#   selector: {"tag"=>{:city=>1}}
#   options:  {}
#   class:    Band
#   embedded: false>

Condition Combination Using $eq / $regex#

Minor change: when using the where, and, or, and nor methods on Criteria objects and providing multiple conditions on the same field in the same argument using the symbol operator syntax, conditions may be combined using $eq or $regex operators, as appropriate, instead of $and.

Mongoid 7.3 behavior:

Band.where(year: 2020, :year.gt => 1960)
# =>
# #<Mongoid::Criteria
#   selector: {"year"=>{"$eq"=>2020, "$gt"=>1960}}
#   options:  {}
#   class:    Band
#   embedded: false>

Band.where(name: /A/, :name.ne => 'Astral')
# =>
# #<Mongoid::Criteria
#   selector: {"name"=>{"$regex"=>/A/, "$ne"=>"Astral"}}
#   options:  {}
#   class:    Band
#   embedded: false>

Mongoid 7.2 behavior:

Band.where(year: 2020, :year.gt => 1960)
# =>
# #<Mongoid::Criteria
#   selector: {"year"=>2020, "$and"=>[{"year"=>{"$gt"=>1960}}]}
#   options:  {}
#   class:    Band
#   embedded: false>

Band.where(name: /A/, :name.ne => 'Astral')
# =>
# #<Mongoid::Criteria
#   selector: {"name"=>/A/, "$and"=>[{"name"=>{"$ne"=>"Astral"}}]}
#   options:  {}
#   class:    Band
#   embedded: false>

The $regex operator is used when the value is a regular expression, i.e. an instance of Regexp or BSON::Regexp::Raw classes.

When using the not method with multiple conditions provided in the same argument, the conditions are kept together and negated as a group.

Mongoid 7.3 behavior:

Band.not(year: 2020, :year.gt => 1960)
# =>
# #<Mongoid::Criteria
#   selector: {"$and"=>[{"$nor"=>[{"year"=>{"$eq"=>2020, "$gt"=>1960}}]}]}
#   options:  {}
#   class:    Band
#   embedded: false>

Mongoid 7.2 behavior:

Band.not(year: 2020, :year.gt => 1960)
# =>
# #<Mongoid::Criteria
#   selector: {"year"=>{"$ne"=>2020}, "$and"=>[{"$nor"=>[{"year"=>{"$gt"=>1960}}]}]}
#   options:  {}
#   class:    Band
#   embedded: false>

New Embedded Matching Operators#

Mongoid 7.3 adds support for bitwise operators, $comment, $mod and $type operators when embedded matching.

Unaliasing id Field#

It is now possible to remove the id alias in models, to make id a regular field.

Mongoid.purge! and Mongoid.truncate take the global overrides into account#

Minor change: Mongoid.purge! and Mongoid.truncate! now consider global overrides set with Mongoid.override_database and Mongoid.override_client.

Mongoid 7.3 behavior:

Mongoid.override_database("some_other_db")
Band.create!(name: "Garage")
Band.count # => 1
Mongoid.purge! # or Mongoid.truncate!
Band.count # => 0

Mongoid 7.2 behavior:

Mongoid.override_database("some_other_db")
Band.create!(name: "Garage")
Band.count # => 1
Mongoid.purge! # or Mongoid.truncate!
Band.count # => 1

update_one Warnings in upsert#

Mongoid 7.3.5 fixes incorrect usage of the driver’s update_one method from Mongoid’s upsert method. Mongoid’s upsert actually performs a replacing upsert, and Mongoid 7.3.5 and later correctly call replace_one.